I haven't been to that place for a while.Did you report the bug to Apple or check in the Apple Developer Forums? Either of those might have a fix for your problem.
Looks like the following:What does Console say when WiFi disconnects?
I've got the exact same problem too! Wifi keeps dropping right after I upgraded to Lion. I suspect that the Airport drivers got changed and there's a bug somewhere, making it very susceptible to interferences.installed Lion last night first few hours fine but now it can't even find my wireless router
my iPhone and iPad can but the MBP can't