So far we've learned that this Celtics team has a chance to beat teams like the Bucks, Jazz, Magic, Bobcats, and even the Hawks, on any given night.
I still think there are at least 10-12 teams in the league who are so much better that they'll beat the Cs the vast majority of the time. The Celtics are still bad enough to drop plenty of games against teams they can beat -- they've already dropped two out of three against the lowly Bucks.
The Celtics will get better with Rondo's return, although perhaps not at first. But there are other teams expecting to improve, too. The Bucks, for example, are missing a number of key players. The New York teams will get better, too.
Bottom line: the Celtics are one of the ten worst teams in the league. I don't think Rondo's return will change that. Because they're in the East, the Celtics could conceivably make the playoffs despite how bad they are. Still, I don't expect it to happen, thankfully.