Yeah, I think so.. few minutes ago my iPhone blocked itself and displayed an message saying that it need to cold down in order to continue using the device... Looks like it is overheating :s
After 20 minutes I turned it on and the temperature looks normal, but wifi still isn't working!
What a bad luck.. I own a iPhone 2G for 3+ years now and never expected any issue.
Just bought this 4S few days ago and I am experiencing all this problems!
Contacted Apple Brazil (0800-761-0880) and the guy told me that they can't do nothing about my problem. So I went to my local Carrier Shop and they opened a Case with Itautec (Brazilian Authorized Apple Maintenance Provider) within 15 days they will pick up my iPhone and analyze it. Anyways.. it is so much time, I can't use my device 100% due to this wifi and overheating issue, will have to wait and pray to get a new device =/