I'm going with some of us got crap phones.. I'm having the same wifi issue.
Like everyone else, I thought it may have been the router, or maybe just me, but no. It's definitely the phone. I tested it on 2 routers with the same result.
For my phone to show full signal bars (which is at about -45dBm) I had to pretty much touch the routers antenna with my Droid. I moved two feet away from the router, keeping a clear line of sight to it, and it dropped from -45 to -55dBm. At 10 feet away, clear line of sight, it dropped to -85dBm. Around the corner to the next room, I lose signal all together.
I tested a friends Storm2 doing the same thing. Same router. His phone shows -20dBm right next to the router, and in the next room where my Droid would lose signal completely, his Storm2 has shows -60dBm. In other words, the Storm2 works like it should.
Looks like I'll be returning this phone after owning it for 2 days. What a joke.
Update:
Just tested another Droid (Also running 2.2) on the same router, and it works completely fine. Definitely bad hardware on some of the phones.