I like Cody Hodgson's chances in Vancouver. He took an extra year to develop in the OHL last year, which I think makes a huge difference. Sometimes, at age 18 players just aren't ready to make the transition, and forcing them in early could hurt them in the long run. Of the guys on your list, they all should get pretty good ice time, but Tavares is on the team with the least offensive talent around him, so I believe his role will be the largest, and he will produce the most.
Matt Duchene. I can guarantee you, he is going to dominate for the Avs.
EDIT: Keith, I didn't give you a thumbs down. Don't point fingers if you don't know the facts. Also, I'm well aware that Duchene might not be playing in the NHL next season. It's highly likely that he'll go back to Brampton, and if he does I'll be perfectly fine with that. More time to hone his skills will make him that much better of a hockey player.