I just updated My Nexus S to ICS today and everything is working properly except for WiFi. It shows the network's SSID but says it is "Out of range". How can I fix this?
That's right, this is known issue and you are not alone. Unfortunately there is no official way to fix this. The only way to get your WiFi working properly is to remove your SIM card or use American (USA) sim card.
BTW it doesn't depend on whether you updated manually or via official OTA.
I suppose, the problem is with latest kernel which doesn't support other country codes despite US and EU. The new kernel is getting the country code from SIM card and after finding that it's neither EU nor US it's dropping wifi support. Unfortunately I don't know exactly why.
There are some workarounds however, they require Rooted device. You can install custom ROM's (unsigned!) or use some scripts (from here: http://forum.xda-developers.com/showthread.php?t=1372074&page=7)
You can "star" the issue here: http://code.google.com/p/android/issues/detail?id=23262 so as many people would "star" it as more attention it could get.
People also saying that there are some missing features after upgrading like:
P.S: As far as I know Google stopped providing ICS OTA for Nexus S. I hope they are aware of that issue and working on it.