NHL 2K8 specifically tells you what each attribute is for, so I popped it in and compiled the list of attribute explanations for skaters and goalies. (And also corrected 2K's spelling errors)
I hope information this will assist future roster makers.
Skaters
Acceleration: How fast a player can get up to full speed from a dead stop.
Aggressiveness (Aggressive in 2K5 and earlier): How likely a player is to fight, deliver intense body checks, and get called for penalties when stick checking.
Agility: Affects a player's control over his body positioning and enables him to be better at things like shooting and pulling off Superstar Moves.
Balance: How good a player is at staying on their feet and maintaining possession of the puck while being pushed around.
Check Bias: How likely a player is to check someone given the opportunity.
Checking: The ability a player has to deliver bone crunching hits.
Defensive Awareness: How aware a player is of the defensive situation of his team. For example, A high value means they are less likely to be caught out of position and allow an opponent to get a breakaway.
Durability: How fragile a player is. Players with high durability are less likely to get injured.
Endurance: Players with a high endurance rating will get tired slower than those with low ratings.
Face-Off (Faceoff in 2K5 and earlier): How good a player is at taking face-offs.
Grit: How likely a player is to do the dirty work and put their body in harm's way.
Hands: How good a player is at things like receiving a hard pass and turning it into a scoring opportunity. This attribute helps with the Pro Stick as well.
Hustle: How willing a player is to do things like chase down loose pucks, get back on attacks, and put forth maximum effort to be where he needs to be.
Leadership: How good a leader this player is. A high leadership rating will help raise morale and lower fatigue.
Nerve: A measure of how a player performs under pressure, like taking a shot with an impending hit coming.
Offensive Awareness: How aware a player is of the offensive situation of their team.
Pass Bias: How likely a player is to pass the puck instead of shooting it if the shot isn't clear.
Passing: The ability a player has to make fast and accurate passes that are not likely to get intercepted.
Puck Handling: The ability to keep control of the puck and not turn it over. This helps in the range and speed of the Pro Stick as well as Superstar Moves.
Shot Accuracy: A measure of how accurate a player's shots are.
Shot Bias: How likely a player is to shoot the puck instead of passing it.
Shot Power: How much force a player can put behind a shot.
Shot Quickness: How fast a player can get a shot off of their stick blade.
Backhander (Back Hander in 2K5 and earlier): How good a player is at shooting backhanded shots, ones that come off the back side of the stick blade.
One-Timer (One Timer in 2K5 and earlier): How good a player is at shooting a puck on the first touch, after receiving a pass.
Poise: How a player reacts to a game that seems lost or how a big game affects their performance.
Speed: A measure of a player's top speed.
Shovel Garbage: How good a player is at digging out rebounds around the goalie and getting them into the net.
Slap: How good a player is at taking traditional slap shots.
Snap: How good a player is at taking snap shots, quick shots half way between a slap and wrist shot.
Star Power: How much charisma a player has. A player with a high rating is more likely to cause the other team to get rattled.
Composure (Temperament in 2K5 and earlier): How much a player can keep their cool and head in the game. For example, A player with high composure is not going to start a fight when down 4-1.
Toughness: How much punishment a player can take from fighting and being checked.
Wrister: How good a player is at taking wrist shots, a quick shot driven by a flick of the wrist.
Will Fight: Is the player willing to fight?
Goalies
Aggressiveness (Aggressive in 2K5 and earlier): A measure of how likely a player is to chase down loose pucks and play the forecheck.
Angle: How good a goalie is at properly covering the net and eliminating low angle shots.
Anticipation: How good a goalie is at predicting where an offensive play is headed. A high anticipation rating means your goalie is rarely caught by surprise.
Balance: How good a player is at staying on their feet while being pushed around.
Challenge: How far out of the net a goalie is willing to come to stop a breakaway.
Dump Bias: How likely a goalie is to dump the puck out of their zone instead of passing it to a teammate.
Durability: How fragile a player is. A player with high durability will be less prone to injury.
Endurance: Players with a high endurance rating will get tired slower than those with low ratings.
Flexibility: How easy it is for a goalie to get into those awkward twisting save positions. A high flexibility rating means your goalie can flop around for saves with the best of them.
Focus: How good a goalie is at keeping their head in the game and making sound decisions.
Lateral Movement: How good a goalie is at moving side to side. This is important to protect against wraparounds and to react to one timers.
Leadership: A measure of how good a leader this player is. A high leadership rating will help raise morale and lower fatigue.
Nerve: A measure of how a player performs under pressure, like taking a shot with an impending hit coming.
Poise: A measure of how a player reacts to a game that seems lost or how a big game affects their performance. A higher rating means they won't quit even down 5-1 in the 3rd.
Poke Check (PokeCheck in 2K5 and earlier): How good a goalie is at poking the puck away from the opposition.
Positioning: How good a goalie is at moving into the correct position for an optimal save chance.
Puck Control: How good a goalie is at holding onto and passing the puck.
Quickness: The overall speed at which a goalie moves to block a shot or get into position.
Rebound Reaction (Rebound in 2K5 and earlier): How good a goalie is at controlling rebounds and not letting the opposition get a second shot.
Reflexes: How good a goalie is at reacting to a quick shot or a deflection.
Speed: A measure of a player's top speed.
Squareness: How good a goalie is at moving to be directly facing their target.
Star Power: A measure of how much charisma a player has. A player with a high rating is more likely to cause the other team to get rattled.
Composure (Temperament in 2K5 and earlier): A measure of how much a player can keep their cool and head in the game. A player with high composure is not going to start a fight when down 4-1.
Toughness: A measure of how much punishment a player can take from fighting and being checked.
Vision: How good a goalie is at seeing the puck and making a save while being screened, and determining if a shot is going wide or in the net.
Butterfly: A goalie in this stance goes down with their toes pointing towards the posts and their pads meeting in the middle. This creates a wall of padding without any holes, lowering the chances of low angle shots getting in. A high rating means a goalie will favor using this technique over others. It is NOT a measure of how good they are at the style.
Sprawl: A goalie in this stance will be laying on the ice in an attempt to cover as much of the net as possible. A high rating means a goalie will favor using this technique over others. It is NOT a measure of how good they are at the style.
Stacked Pads: A goalie in this stance will place both leg pads together while on their sides creating a small wall. A high rating means a goalie will favor using this technique over others. It is NOT a measure of how good they are at the style.
Standup: A goalie in this stance will stay on their feet while they attempt to make a save. A high rating means a goalie will favor using this technique over others. It is NOT a measure of how good they are at the style.
Stick Down: A goalie in this stance will lay their stick down along the ice to cut off low shots. A high rating means a goalie will favor using this technique over others. It is NOT a measure of how good they are at the style.
Blocker: How good a goalie is at using the blocker pad on their stick hand.
Body: How good a goalie is at using their body to stop a shot.
Glove: How good a goalie is at using their glove hand to snag pucks in the air.
Kick: How good a goalie is at making a kick save with their skate.
Pads: How good a goalie is at stopping pucks using their leg pads.
Stick: How good a goalie is at making saves with their stick.