Sadly enough they didn't have this feature in MM08 either. But honestly it didn't effect online play, I knew who my players were and that was enough.
As frustrating as that is, not many of us play online anyway, there is a bigger chance you'll be playing offline more. Because they have so much added this season.
Give them a break they can't do everything right in it's first few years of development.
So far all the 09 titles have come out pretty good even with flaws, I don't see this game being any different.
No online names whooptie doooo! How will it play online, smooth servers, nice online menu setups, etc. These are important things, not some crap about names usage..
Be patient and non judgmental! Lets see what they offer us as a full package before kicking it to the curve over 1 thing.