I hate that whole "we're going to kill off one of the characters so you better watch!" type advertising. Especially when they then try to fake you out about who it is during the show. (Note, this applies to famous books (aka Harry Potter) as well, damn it!)
However as long as they were going to do it that was an interesting way to do it. In fact it was almost as if they were playing off of my particular annoyances.
I'm glad it wasn't the cute goth geek girl, otherwise my primary motivation to watch the show would be gone. However i didn't think she was a likely target anyways given how she spends 99% of her time in the lab.
So i wonder if they just felt they needed to pull up the ratings, if they're planing on canceling the show anyways so it didn't matter (hope not!) or if that actor wanted to quit for some reason.