Yes.
Although I like the season so far and Cristina's missing isn't (surprisingly) that big, I wish we'd see more of the older characters that are gone (and not dead).
I'd like to know what happened to Izzie after she left. Maybe she could come back with a patient that has something only the Grey's hospital can fix so Alex, Meredith and her have the chance to find their peace.
I'd also like Addison to come back for a few episodes.
But it won't happen anyway.