Don't worry, there aren't any spoilers. The video above will show you what enemies you'll face off, what character leveling is like, and what you can do in the hub city of Sanctuary. It's a very basic look at what Borderlands 2 is all about, without getting too much into the goodest stuff. Yes, goodest. Shush.
As a warning, this content was captured after I finished the game. So I'm at a higher level, and I'll take down enemies pretty easily. The video starts off in New Game + mode, though, so you can get a sense of what a more realistic battle is like. And then it proceeds into regular mode so I can show off a bigger range of enemies.