ultrasn0w unlock: After redsn0w is officially released with the new Cydia and kernel patches, we’ll be able to assess the unlock situation. It’s already looking very promising though, so expect the unlock for the 3G and 3GS to be coming this week. The i4 unlock is taking more effort though, and no further concrete info is available about that yet.
The iPhone 3G and 3GS are on track to be unlocked within the week, but the iPhone 4 is proving to be a tough nut to crack, and may take quite a bit longer to unlock.
As always, backup everything. And don’t bug the devs.