Because the Raptors and Nets were the two front runners for Atlantic, and Boston beat them both. Hence Boston - according to these early results - will win Atlantic and can only finish as low as 3rd seed in the East. So they'll at least make it to the second round of the playoffs. Of course the team to beat in the East is still Detroit in my opinion. I don't see anyone else beating them. Orlando, Cavs, Miami, Washington? Can't see any of those winning over Boston.
That is not the final rankings. we don't care about that. Even if we are at #1, so what? Actually, they are the only team unbeaten so far as you said. I am waiting for the firt game vs Boston. That is the most important thing Rockets can prove himself.
New Jersey and the Raptors are two of the top eastern conference teams (nevermind I don't think they could make the playoffs in the West), but yeah, the other teams they played were all pretty crappy.