I know for a fact Apple hasn't banned everyone with a hacked iPhone/iPod Touch, as I am one of the following, and my device works fine.

US law actually states that if you own the device you are able to do with that device as you please, so I doubt Apple wants to tread too much in legal waters with the FCC right now, since there direction has been to allow this to happen.

Technically though, they can brick your phone in future updates, and this caused quite a stir when people thought that they did just that in the update to OS not so far ago. So I wouldn't say that just because you have hacked your phone/iPod that your in the clear with updates.

The news that has been circulating has been of two prominent hackers that have had their accounts locked. This is common practice for wrong passwords, but may have been Apple's doing for a warning. The actual facts though, like most of Apple's internal decisions, have remained a mystery to the general public.

I personally feel that Apple's app store only model is an affront to the Open Source community in general, but I also realize that in the US this is dictated by the Wireless carriers and Apple itself. Eventually we'll move to the more open cell phone status of the east, S. Korea and Japan, but it won't happen overnight. In the meantime, I would suggest that you listen and watch the news, if your iPhone/iPod touch is already hacked be prepared to restore to an older firmware, and if not be cautious that Apple may brick future upgrades.