The first free, open source iPhone unlocking software has been released.
There's really not much more to say about this other than it does pretty much what iPhoneSIMfree does, but that you don't have to pay $99. There are no guarantees that the software will work with future firmware versions, no guarantees that it won't hose your iPhone and no guarantees that Apple won't release an update to make unlocking future firmware versions trickier.
I doubt that customers who jumped the gun and paid $99 won't be receiving any kind of voucher or store credit from the makers of iPhoneSIMfree.
If you want to take a peek at the source code, it's available here.