While I will always regard Rondo as one of my favorite Celtics to watch (you could argue he's one of the most exciting players in history) he was no longer a fit for this team. The Celtics defense, which has shown to be their greatest weakness this season, will be drastically improved with the addition of Wright, and the subtraction of Rondo. I respect Rondo and all but for the past few seasons he's been playing some pretty lackluster D. That's hard to deny. Wright on the other hand, has made a name for himself as a stellar interior defender/rim protector, something the Celtics have been sorely lacking for about 4 years.
I know people don't expect much from Nelson, but it's often forgot he's a former all star and was the 2nd best player on a team that made the finals. I know that was while ago, but it's not like his shooting stroke has suffered. I expect Nelson to get a good chunk of playing time at PG behind Marcus Smart, who will eventually end up starting, and will also benefit from Rondo's departure. As for Jae Crowder - He doesn't have all that high of a ceiling but could blossom into a James Posey type role player which would be amazing.
This team is going to be better. Think about it, they're only 5 games under .500 with only 23 games having been played, a lot better than a lot of people projected. I'm excited to see what Stevens can have these guy do.
more trades to come before the deadline though probably.