OS X 10.7.2 has done NOTHING to resolve the conflict between the bluetooth kext driver and the kext WiFi driver.
it's clear on my MacBook Air 11" 2011 that when I am connected to 802.11g wifi with bluetooth Off.
open Terminal--- run a constant ping to the IP address of my name server. steady results in the 2-3ms range.
turn on Bluetooth
watch as packet times drastically increase to the 180-260ms range and even DROP packets
if the WiFi is ever turned off and back on, the WiFi connection will not even re-connect.
(various messages seen in Console)
anyway, the only relevant fix appears to be downgrading the kext WiFi driver itself as documented here:
<http://thoughts.maayank.com/2011/08/wireless-problems-with-macbook-air-and.html>
I am unsure if the driver alone is to blame or if actual radio signal interference is possible between the chipsets.