Up to now, we've only allowed draft pick trading for two years at a time and only the first three rounds of picks.
Starting immediately, teams can trade picks for up to four years and picks can be dealt from the 1st through 5th rounds.
Not sure it'll be much of an appreciable difference, I figure that it might for some teams.
If you want to track your picks, I've got a
Google Docs spreadsheet that always keeps track of picks that are traded.