I'm just about lvl 13 with my hunter and am just taking on the Sledge Quest. 
One thing has me concerned about this game.  I heard this there was going to be a massive world, is the Arid Badlands just the tip of the ice berg, or is that basically it (the arid badlands being the main hub, with dungeon instances). I really don't want to rush this game, I hate beating games and having them be over before you know it. 
 
So from anyone with experience, and try to hold the spoilers.  Is there much more waiting for me outside of the Badlands?

The Arid Badlands are only the beginning my friend.

" The Arid Badlands are only the beginning my friend. "

F'n Sweet, thanks bros.  YES so pumped about the rest of the game!!

Just wait until you find the Rust Commons...

I've gotta say that I'm thoroughly impressed with the little chunk of Pandora that they've created.  I'm really curious now about where Jakob's Cove will be located, and I'm already looking forward to the rest of the stuff they'll be doing with the DLC down the line. 
 
Frankly, this game puts Fallout 3 to goddamn SHAME!

I am lv6 at moment and just loving this game like crazy.  The game is better then I thought it was going to be!