Sherif Hashim confirmed a few days ago that the exploit he discovered last year can be used to unlock the 02.10.04 and 03.10.01 basebands of iOS 4.1/4.2.1 for iPhone 4. The Dev Team announced that the unlock solution for iPhone 4 will be available only after the release of iOS 4.3 and if what Sherif Hashim said is confirmed then you will be able to decode iPhone 4 on iOS 4.1/4.2.1 and maybe even iOS 4.3 if the Dev Team has found an exploit and for this baseband. For the iPhone 3G/3GS there is no news yet, but there will probably be a solution that will allow you to downgrade from the iPad baseband.
In conclusion, after the release of iOS 4.3 the basebands 02.10.04 and 03.10.01 should be able to be decoded!
