Stated in the title, going through tons of fixes.
http://www.keenandgraev.com/2012/05/12/diablo-3-stuck-updating-setup-files-

Still refuses to work.

Set-up goes from Launching Blizzard launcher, back to Updating Setup files, back to launching blizzard launcher *repeat*

Currently using Windows 7 64-bit OS and i tried running the thing on admin / putting it on windows xp service pack 3. Still absolutely nothing. And i tried using my friends CD. Same problem occurs.

Whats the deal with this Agent thing Blizzard?

I really was not expecting a 60 dollar pre-order to go down the drains for such a highly anticipated game.