The word on the street is that Apple, whilst looking for ways ensure customers did not brick their iPhones after a future software update (namely, the one including the iTunes WiFi Music Store), have simply chosen to take the somewhat easier route of stating "Users who make unauthorized modifications to the software on their iPhone violate their iPhone software license agreement and void their warranty. The permanent inability to use an iPhone due to installing unlocking software is not covered under the iPhone's warranty.".
The press release also goes on to tell us that iPhone users can expect to receive the Software Upgrade this week, leaving people in the lurch until then to see whether this Doomsday-esque scenario plays out as Apple says. If you want to be on the safe side, you might try Erica's relocking procedure (still in the very early testing stages!).