Ya, there's a retail Box available on Sept 18th. You can also pre-order that as well from GameStop, and probably many many other retailers. It WILL need Steam to activate, so if you don't have Steam you will need to register. Steam's free BTW.
I just pre-ordered this on Steam a couple of days ago and I'm just finishing yet another playthrough of Borderlands GOTY. I hope they allow CH Trainers IN SINGLE PLAYER since GearBox's code didn't seem to let them work well in the fist game. Man, I hope WillowTree also works or they get a new version out fast. I've had 12 guns saved in WillowTree that I keep giving new characters and leveling them up with the chars... no need to loot white, green or blue weapons except for cash ( though no real need for cash either ) .
Wow i must be LUCKY my trainer works great with Borderlands GOTY with the latest patch No problems at all.The latest patch is 1.41 just enjoying the game this week and alls well.