"Grey's Anatomy": Izzie in a Tizzy

Sorry, I couldn't resist the corny headline...

Warning: The remainder of this post contains details about last night's episode of "Grey's Anatomy"...

So, Izzie and George actually did it. And neither one of them is handling it very well, as it seems like Izzie may care more about George than even she knew.

Which leads me to a question. Does Izzie just turn feelings on and off like a light switch? Didn't Denny, the great love of her life, just die? And now that I think about it, didn't she fall head over heels for him a little too quickly as well?

Thoughts?