If it's as as serious as the article claims, I'll be quite shocked. If someone were to release an iPhone worm that spreads via SMS, then Apple would be devastated.
But they would have better infrastructure to deal with it than any other cell provider. (iTunes, retail stores, etc.)
I'm pretty sure AT&T could do some packet filtering and block those bad sms.
I'm sure AT&T would love that. Virus protection, now from AT&T, only $20 more per month to protect your iPhone.
I don't think I'd trust them to keep up with all the new threats.
AT&T isn't the only carrier with iPhones, though. I can't imagine Telcel bothering, for example.
Except that competing smartphones (BlackBerry, Android, Pre, etc) almost all do OTA updates which is more reliable and doesn't require the user to keep up to date on their computer.
Do you know for sure that the iPhone doesn't support OTA updates, or are you just guessing based on the fact that Apple hasn't done one yet?