For any Mac users, beware of a potentially annoying bug when installing the new OS X Lion. It apparently has serious issues that affect your WiFi connections with PSN.
I spent hours on the Mac Forums trying to figure out why I couldn't get on PSN via WiFi and it is related to the new OS. Stick with Snow Leopard until the update fixes this.
I bit the bullet and finally hardwired the PS3. Had to run about 75' of coax from the basement interface to my family room, drill through the floor, cut up a wall, and fish the cable, but I finally got it done. Hopefully many more 4 bar connections in the future and maybe even a "Host Pro" or 2.
Hope this helps the Apple guys out there.