You could try some one on one play to get him involved at the basic level and allow him to integrate better with learning the game. You know, no embarrassment with not knowing the game.
Another thing you can do is to have everyone get together to work out characters and make them all from the same town/village. Then give them some kind of starting mission, for instance, the leader of the town/village goes to their respective masters and requires a group of new recruits to do some kind of job for him/her. That way, all of the characters know each other and have a reason to all be working together from the start.
If I think of anything else, I'll post it.
Oh, and from what I've seen about 4e, I'm going back to Basic Role Playing, which is the system that RuneQuest and Call of Cthulhu use.