I really don't know... right now I imagine Katherine using the dagger on Klaus and (as she's a vampire) dying too. That would also allow the possibility that Klaus returns in episode 3 when someone pulls the dagger out again. But I could also imagine many other things to happen and I can't really decide which one I find most likely...
Of course things might change a lot after the next episode, so everyone may of course re-pick after each episode (unless he already died, obviously).

Klaus committing suicide is unlikely...
It might be Elena or Damon or Bonnie or Katherine. Or hell, maybe Elijah. Can't see anyone else killing him.

he's THE vampire, come on, i don't think he could be killed in a few episodes ;D

@KathyHalliwell: :D Yeah, I know. I don't think anyone will pick the suicide, but I wanted to offer all possible options.

@peppersalt: With "in the end" I didn't necessarily mean in the end of this season (it might as well happen in season 3). Did you understand it like that?

Yeah, I'm guessing end of S3 but with TVD pace I don't even know...

I'm guessing Elena, but Damon/Katherine/Bonnie will most likely have major roles.

I don't think they're going to kill Klaus for awhile but I have a weird feeling it might be Elena to eventually figure out a way! :)

@JAlanaE: yeah, I guess, I misunderstood :)

Now that he's gonna be back. But I actually have no clue. We'll see :D

I Don't Think Klaus Is Gonna Die For A Long Time But When He Does I Think It's Gonna Be A Group Thing Involving Almost Everyone But I Picked Elijah Because I Think In The End He'll Be The One To Actually Kill Him.