I agree that the Celts keeping Rondo over Telfair was a GREAT move. Telfair's future is not looking good at all, while Rondo has potential to be an all-star in 3-5 years.
Anyway, there really isn't need to panic. The Celtics have obviously improved by leaps and bounds but IMO aren't more than a 50 win team right now (which the Nets can be too). Rondo will be a superb point guard in a few years but right now is too young, undertalented and inexperienced to be the starting point guard for a team that wants to conted for a title. If the Celtics manage to sign Brevin Knight, that'll be huge for them as Rondo can learn from him and fill in the role of backup PG (which is currently a gaping hole in Boston's lineup). Plus, Knight is a proven distributer (anyone remember his incredible season with Charlotte a few years back? Imagine what wonders he can do with 3 all-star scorers to pass to. But the Celtics signing him is unlikely IMO. I can see him signing a backup role with a powerhouse team in the west (sort of like Vaughn signing with the Spurs last offseason).
With their current lineup, I don't see Boston winning a title. They have big holes all over their lineup (that's what happens when you trade 5 for 1) and don't have enough money to sign 2-3 decent players. Their biggest fault is that they have no backup point guard for Rondo and obviously such a young guy can't play over 30, max 35 mpg and man such an important position alone. Scalabrine and Glen Davis are miminaly effectual at best, Powe and Perkins are ok but neither is staring material. Tony Allen (if he can get past his mental and off-court troubles and his huge surgery) is a good backup at the 2/3 and plays very good defense on the wing, but if he doesn't play well the Celtics' only other backup at 2/3 is 19 year old 2nd rounder Gabe Pruitt, who probably won't be signed this season anyway. Imagine if Pierce, Allen or Garnett get injured? Even if it's only for 10 games each, the Celtics have nobody who can carry the load off the bench. No backup center (or if KG plays center and Powe starts, a logjam of 3rd string PF's on the bench), no backup point guard, one backup for both guard positions (Tony Allen) and some decent-at-best players (Wallace, Veal and Davis) who play the basically the same positions. I'm not so high on the Celtics right now, but who knows, if KG, Allen and Pierce all stay healthy, Tony Allen plays like he did before he got injured and the Celtics manage to sign at least 2 more decent backups (NBA material), the Celtics may win 55 games this season. If not, maybe they'll surprise everyone and win only 45. Who knows?
As for the Nets, I'm satisfied with the current lineup and I think we still have a shot to win the division if we win 50+ games, which isn't so far fetched with a healthy Krstic (I think everyone is underestimating his affect on the team) and the addition of Magloire, plus probably one more benchie of Eddie House material. I wouldn't complain if the Nets traded for O'Neal, but only after the season starts and the current lineup proves to be underwhelming or if management are SURE that a trade like that would improve the team to ECF material. Taking a gamble in the offseason could work (the team wins 55 games, contends for the ECF and O'Neal averages 20 and 10) and could backfire (The team hovers just above .500, O'Neal dissapoints, Krstic averages 18/8 in Indiana and Williams looks like the next coming of Kidd again instead of the next Steve Francis).
The division is obviously much tougher now than in the last couple of seasons, but it's still winnable. Toronto have pretty much stood pat in terms of talent, Boston has become a contender, New York seem dangerous but will probably underwhelm again and Philly are the worst team in the leauge. Meanwhile, the Nets are stuck in the middle and can finish anywhere from 1st place in the division and a 3rd seed, to 2nd/3rd place and another 6th/7th/8th seed to 4th place and a place in the lottery. Anything could happen and the season looks pretty unpredictable right now.