It looks like a cool game? Can anyone Tell me some good stuff?

And the bad stuff?
Is it worth buying?

This game is fantastic, absolute must-buy.

Good stuff - Everything. Combat is great, quests are entertaining (and there's lots of them, dammit), game is long, fantastic co-op play etc.

Bad Stuff - Bad story, fighting over loot against greedy assholes is not fun, and the world isn't too big (it's a fair size though)

What's the world like in size compared to Prototype or Fallout 3?

Not even close to Fallout 3, which takes over an hour to cross just from one end to another, let alone fully explore, but I'd say it's a bit bigger than Prototype, although it's a hard comparison since Fallout 3's and Prototype's worlds are open-ended, and Borderlands is divided into several (rather large) areas.

haha aw i was planning on buying uncharted 2 after exams in like a week, but now i dunno if i should buy this one now...

I've heard that the aiming or shooting is a lot like CoD4
is that true?

if it is..i am sure to be a fair shooter from the start!
perhaps even a master sniper *giggles with joy*

Yeah, it's got the same control-scheme as CoD4 and aiming and shooting feels similar, if not identical. However, that's as far as the similarities go.

From what this game looks like in gameplay footage... I may get it, depending on if I can get some competent friends to play with me, and stand my constant yelling in a high-pitched voice about someone taking my high-powered assualt rifle, but this game has some good graphics, gameplay and over 17 million weapons. What more could you ask for?

quote Zhents

over 17 million weapons.

But the trailer said 87 billion...
I ish confushed...

It is just a marketing thing, there are over 17 million weapons that are recorded, but there are still combinations that even the creaters of the game don't even know about still.

who has this and uncharted 2? I can't decide between the two, well 3, uncharted 2 this and mw 2.

I have both this and Uncharted 2. This game takes the win, methinks. UC2 is awesome but you may like it more since it has multiplayer as well as co-op missions and campaign, whereas Borderlands just has single player and co-op, although you can kind of do a 4 player-deathmatch in arenas you find.