Is Katherine Heigl being killed off Grey's Anatomy? Literally and/or figuratively?

This question has been raging for months ... many months in fact.

The latest from E! Online is that although nothing is official, it's looking "very likely" that both Heigl and T.R. Knight will sail off into an ABC-free sunset come the end of Season Five.

"The legal papers just need to be signed," says one Grey's Anatomy Insider reportedly familiar with the situation regarding the two acclaimed stars.

So, are the months-long rumors true that Izzie will die? If so, was bringing Denny back a mistake at first glance, but retrospectively a brilliant way to build up to her death?

At first glance, it would appear so, given her condition. However, it has been speculated that ABC will only release her from her contract if she agrees to future guest spots.

And if Izzie does leave, for any reason, what does that mean for her (living) love interest, Alex Karev? Also, how sorely would George O'Malley (T.R.) be missed? Would Seattle Grace be the same? Can the show survive without the two?

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.