Just to ease some people's minds:
Yesterday I installed the leaked 2.0 firmware along with a iPhone-page-worth or so of free apps and Enigmo. They all ran fine, if not with a 100% crash free experience. Basically, everything worked as far as I could tell.
Today, I've just connected my iPhone to my Macbook, selected "Restore" in iTunes 7.7, and let it do it's thing. The firmware is now updated to the final build and I'm syncing my music and such back to the iPhone.
Also I just got a text from my friend, so I can confirm network (re)activation. To note, I've never jailbroken or unlocked, and I'm using an 8GB iPhone with AT&T in Louisiana (south U.S.).
Just wanted to confirm a successful update/restore from leaked firmware to legit firmware with no under-the-table techniques.