I'm getting the feeling that Derek needs to be someone's "knight in shining whatever." and that's why he never looked at Addison the way he looks at Meredith, which as a basis for a long-term relationship may not be a good thing (for Meredith or Derek). Or maybe it will. Who knows, but he definitely seems to have a need to fix this broken little bird. What happens if she gets to where she's not broken anymore.
As for the correspondent show that the "Denny" actor is going to be on. I didn't get the impression that it had been put on hold. Isn't it supposed to start in May (or whenever the summer replacement shows start)?