Ok i liked the first portal but im not sure if should buy this game.  None of my friends are getting it and i don't really wanna play co op with random xbla people so i would probably only play single player so im must wondering if the single player is good enough and long enough to justify a $60 or should i just wait for the price of it to drop?

Good enough? Yes. Long enough? No, not for my budget. I beat it in under 5 hours, many beat it in 7. If that range is good enough for you, definitely get it. If not, you could always wait till it gets cheaper, or rent it. Its basicly void of other things to do besides co-op. There is no challenge rooms, no advanced testing chambers. Just the story mode and co-op.

Do you have a second controller? I heard it has split screen and I'm planning to play with my little bro when I get it.

I am about 2/3 done with the Single-player, and I would say yes. I have spent about 4-5 hours getting there, so I'll clock it around 6-8 hours. Normally I would think that would be to short for a game, but it's just so good I don't mind much. It seems there are a lot of secrets I did not find as well, as my girlfriend said she found a lot of stuff. She spent about 4-5 hours getting 1/3 of it done.
So I am going to just start over again once I beat it.
But yeah, as luce says, I think it's suppose to have split-screen on 360. You should verify that first though.

Maybe i'll rent it one day on consoles and but it when it's dirt cheap on the pc later.

Guys I have two questions and I think someone can answer them. First, is local multiplayer supported on the PC version (keyboard and gamepad)? And second, should I play the single player before? I will bring a friend to play with me friday and was going to buy it first thing in the morning. 

Thanks for the info everybody i think im just gonna wait till the price drops a bit.

It's only 6 hours.. but they're some of the best 6 hours you'll ever spend playing a game. :D

Yes. Absolutely.

I have to say, even being unlikely to play the co-op and finishing the rest in a short time, I'm still damn tempted to get this now. Usually I don't have a problem with waiting, but ugh! So conflicted.

I beat the game after about 7 or 8 hours and I loved every moment of it, so much that I played it pretty much non-stop the entire day yesterday, which I've never done with any game before.

If you are afraid of spoilers you should get it now. The story is a pretty big part of the game. And spoilers will probably be all over internet in a month or so, just like  with portal 1.

Personally, I'd say yes. It took me about 7-8 hours to complete and I enjoyed every minute of it.

It's about 5 hours long for single player. It is an incredible experience, but value depends on your budget I suppose. You should play the first game if you haven't already. Portal 2 will still be great for you in a few months if you decide to wait, as long as you avoid spoilers as much as possible.

 Its basicly void of other things to do besides co-op. There is no challenge rooms, no advanced testing chambers. Just the story mode and co-op. "

It really depends on how much you liked the first one. If you really liked the first one (as I did), then Portal 2's singleplayer is just fine. If you only moderately, or only half-heartedly liked it, then you might want to wait for a price drop.