I seriously never thought I would say this, but I didn't miss Izzie at all! Even with this episode, I think the rest of the cast made more of an impression on me than her return. I was really into her in the first 3-4 seasons, but now I find her over used and washed up (not Katherine, but her character). I just don't see what else they could do with that character to keep it interesting.
Also the cheap soap crap of "misunderstanding" is going to play a key role in the rest of the season for Izzie's character. I said it last week and this week it was confirmed. Alex was going to get mad at Izzie for not having gone to him and talked things out. He's right, she's his wife and she should of had more trust in him. Of course this was the only way the writers could get Katherine time off, but in doing so it just created more of a dislike for her character. I can see why a lot of people find her character so annoying now. But I still love her.