I was having a lot of problems with my WiFi connection on my MBP. The connection would drop about every 10-15mins and then reconnect 15-30 secs later. The access point I was using was a ZyXel ZyAir G-3000. I have never had a problem with the ZyAir AP, up until this point I would call it bullet proof.
To trouble shoot this problem I went to BestBuy and picked up a D-link DIR-655 Router/Access Point to test with. I have not had a single drop on the MacBook Pro since installing the device. I have never been a huge D-Link fan but I have been very impressed with this router/access point.
I have come to the conclusion that Apple does have an issue with the chip set they are using for WiFi that shows up with certain hardware combination's/environments.
In my setup the D-Link DIR-655 has worked without any issues.