I've just managed to catch up with the last 4 episodes (it's amazing how quickly you can fall behind!)
Anyway, I agree with cshapiro about Derek's reaction. It was majorly over the top. I guess though that Grey's is more about the Drama and less about the Medicine and I think if you accept that then it doesn't seem so bad.
I'm glad that Izzy has finally realised something is wrong with her. At last !! So, is it going to be related to the mole? I mean, how would melanoma make you hallucinate? Maybe they can relate this some how, but I guess it will be something extremely unusual. Or did the Dermatologist Dr find something else underlying? I guess we will have to wait and see.
I haven't watched PP yet so it was nice to see Addi back. I thought it was a bit insensitive of Derek's friends to be talking about the song that he wrote for Addi when they got married. It's like, get over it, they are not together anymore !!
Sorry cshapiro but I found the fight scene hilarious!! Totally over the top and all, but I still found it funny. Mark picked a bad time to tell Derek, that's for sure. However, I think it was a bit extreme of Derek to warn Mark off Lexie in the first place.