With the Celtics, it will come down to keeping them healthy. If the three can stay physically intact, and learn to work together, they should be able to overcome how thin the bench is. After all, they've got some good young athletes to help fill out the roster -- guys who can be excellent role players if not called on to do the heavy lifting. Chances are, though, the stars won't end up meshing that well, or one of them will get a nagging injury, and they won't be able to play up to potential.
Regardless, they'll need a point guard to step up. I think that with Kevin Garnett at power forward, they don't need a great center. But somebody has got to distribute the ball. I don't think they'll do well if Allen has to act as the de facto point guard, because they could quickly become one-dimensional.
I'm very jazzed about the Eagles, but it's hard to know how good they are, since they've yet to play any great teams. They've played two really good teams, but not any top-ten types. Matt Ryan sure has looked good, though. I had season tickets for years, so I've seen a lot of good QBs at BC (Matt and Tim Hasselbeck, Glenn Foley, and Paul Peterson were all better than the national media ever gave them credit for being, when they were at BC). But Ryan's the best from my era... taking that title from Matt Hasselbeck. Probably the best since Flutie. Barring a bad injury, at his present pace he should be a first-round draftee, even if he misses out on te Heisman.