I'm also experiencing this on a 3rd generation iPad. Disable WiFi assist won't help since I have no 3G on this, only Wifi.
I tried everything! I lost my WHOLE Saturday last weekend to try to make it work, from 9 Am until 2 AM! This is crazy and a lack of respect for clients to launch a system with this kind of flaw! It's inadmissible!
I have tried the 9.2 Beta release and I can tell you it doesn't work either. Also problem looks kind of random, some users complaint of not being able to connect to enterprise networks but they are able to connect at home, my problem is completely the opposite. I can connect to enterprise networks only, any other network.. closed, open, whatever won't work. Wifi hotspot from an Android also works. So what can I do to use my cheap 600 Dollars equipment (ironic)??? use data from my Android to feed wifi to my iPad and send the data bill to Apple???
Come on Apple!