Ipad 3 and my 4s are both working on my end. I have only tried it with my wifi connection at home with a time capsule as the router.
Fwiw, here's the process i did, when i restored to ios 6, I setup the wifi first thru the ipad and then restored from backup. I setup everything from the ipad first and when I got to the last part of the setup (setup ipad as new, restore from icloud and restore from itunes backup) I tapped restore from itunes backup.
Did this for both my devices and haven't experienced wifi issues. (Hope it stays that way)