Alright, I'm not officially sure that this is a leak, but it doesn't seem like Obsidian put this out. Very minor opening spoilers obviously. Doesn't seem too substantial, but proceed at your own risk.

Click click
  
Environment looks cool, and I think Perry sounds pretty good.

dope bumpin' this shit.

Not clicking, probably a smart move. I want no spoilers.

Well, it already just from that cutscene seems to have more personality than Fallout 3, which is an excellent thing, IMO.  I really can't fucking wait for this game. 
 
Spoilers aren't too substantial, just basically if you know who the main character is, than you should know everything in this opening.

Matthew Perry seems to be doing a good job so far from the few lines I heard. He was apparently a huge fan of Fallout 3, so I'm glad he got to do work in New Vegas.  
 
ALSO TO CLARIFY 
 
the "one month later" part seems to have been edited in, so don't take that part as fact. 

cut scenes? wtf

Must...resist...clicking...link.

How can you be spoiled by the opening cutscene where the only things that happen are your typical Fallout trailer stuff and then a few seconds of setup story you already know if you've read any coverage of the game at all, and stuff that will probably be on the back of the box? 
 
Looks great. The only jarring thing is that it isn't all a wasteland setting like I'm used to in a Fallout game. It'll also be a little disappointing going back to an engine that looks pretty good but has horrible animations. But that's the only disappointment. I pumped hundreds of hours into Fallout 3, and I think it's been a long enough time that more of that will be welcome.

The only spoiler in that cut-scene is it shows the "important" item the courier was carrying. 

I hope that it's an early version. It looks unpolished.

Anyone else think that the CG in it looked awful? 

It looks insanely rushed...

Looked good. 

This  looks actually pretty awesome, I hope to god that they have changed the clunky combat system. Felt like I was spending my life running backwards.

I'm excited.

Clickity clack ah caan't resist!

i dunno about leak but that was siick

" i dunno about leak but that was siick "

I saw that a few days ago. I'm surprised it hasn't been posted actually. I guess I'm always thinking it already has or else I'd have done it. ANYWAYS, looks good! It certainly looks like it'll have more story than Fallout 3, or maybe that's just what I'm hoping.

i'm more excited by Falout NV than halo Reach or Call of Duty or any other game... 
 
I have to wait till the 22nd of october to finally play it...what a torture ;-)

This is just hyping me even more. I should go play Fallout 3 again, until NV is out.

I won't believe it until I hear Mr Ron Perlman say

War. War never changes 

That was thupadope.

that guy has the coolest suit ever.
 
literally cannot wait

I want my Vegas experience as pure as possible, so I'm not going to click. I'm sure it's sick though.

Ah, what the heck I'll give it a look-see. Spoilers in Fallout don't bother me.
 
I didn't play Fallout 3 for the story, I put in 70 odd hours before I even finished it. Something tells me I won't care about care much about New Vegas' story either.