What's interestingly come from such sleuthing, is the hint that there'll be Avatar rewards for some achievements in L4D2. You'll be able to outfit you Xbox Live Avatar with items like the Med Kit or the Frying Pan. It's a neat way to show off what you've done in a game, and Avatar rewards are certainly more upfront that achievements (forget all that reading no one wants to do).
My question is this: Do Avatar rewards justify a purchase of Left 4 Dead 2 on 360 instead of PC? I just don't know how to justify buying a Valve-developed and published game on a console instead of PC, seeing as how PC has always proven to be the lead platform for Valve.
Personally, unless I find out that I won't be able to run L4D2 on my computer, I probably won't be enticed by Avatar rewards.