I have noticed a weak wifi connection on my Nexus S glade to hear its not just my phone. Must likley it just needs a software
update to fix the issue unless you have a older router? than can be the issue aswell.
wifi drops/reconnects maybe 1 out 8 uses, more if used over a prolonged period. however, going the opposite way (using the phone as a wifi hotspot) ive had no trouble so far though the speeds are still slow but that is dependant on the fido network