According to an attorney on Twitter, although it's now legal to jailbreak an iPhone, Apple can still state it's a violation of their warranty and deny service -- as recently seen with someone who jailbreaked their iPad (which heated up) and was denied service: http://snurl.com/zv7gc
If, somehow, hardware manufacturers were required to extend warranty coverage to unsanctioned modifications, we'd see a lot of push-back against this in the near future. The extra burden to vendors would make a good argument against it, but the great thing is that as it stands, it's hard to argue against this without sounding anti-consumer.
It would really be interesting for someone to try to make an argument under this law that Apple must show that jailbreaking the device caused the malfunction before refusing service.
That said, mentioning the guy who dropped his iPad and was pretty much asking for a favor (Apple does not cover accidental damage) is silly. In practice, Apple actually /does/ ignore jailbroken-nes ls of phones when it comes to serious hardware errors, and they have even stated as much in their DMCA commentary.
This is getting a lot of play in the MSM. TV news is even talking about it -- local, not just network (just like Consumer Reports and the iPhone 4 antenna). If this leads to a lot of people jailbreaking, I wonder if this could lead to a growing alternate market for iPhone apps vs the App Store.