According to a tweet posted by GeoHotz a couple of minutes ago, the Blacksn0w tool to Unlock the iPhone on baseband 05.11.07 shall work for both the iPhone 3G and the iPhone 3GS.
This is big news for all users out there since they would be able to unlock the iPhone recently purchased from an Apple store with the new baseband pre-loaded.
Blacksn0w would be able to be used once the device has been Jailbroken using Blackra1n which is an all-in-one Jailbreaking tool released by GeoHotz, compatible with all models of the iPhone and the iPod Touch. Once the device has been Blackra1n'd, it will then be able to be unlocked with Blacksn0w and be used with any carrier.
The video posted below shows a demo of GeoHotz making a phone-call with his iPhone on the baseband 05.11.07 through an unsupported carrier (T-mobile).
There is no ETA for the release of the Blacksn0w tool by GeoHotz but we make a guess that it will be released on the 4th of November. Keep all fingers crossed for this one.
A detailed tutorial will be posted shortly after the tool is released. Check back regularly!