This seems like a lot at first glimpse, but I will make my argument by defending that it is actually pretty fair.
Glen Davis is a high octane player off the bench who provides clutch scoring and some rebounding and defense. Although not a star, he is capable of putting up good numbers nightly and outhustling most players. However, there is somewhat of a "cap" on what he can give you consistently. To me, he would be the main attraction in this trade.
Jermaine O'Neal's contract only lasts one year beyond this one. At worst, he gives Chicago a veteran big that when healthy can contribute. With Shaq back, Garnett healthy, and bigs like Erden showing they can contribute at the NBA level, one could argue that Jermaine's presence on this squad is negligible.
Kendrick Perkins's effect on the Celtics has been huge, but let's not forget how the Celtics have been playing without him (not too poorly).
The main drawback is that Boozer has had some injury problems. But let's not forget that this guy is still pretty young and is a 20/10 player. Although he may not be known for his defense, being on a team like the Celtics would help him adjust, as long as he knows how to make rotations. His five years is concerning, but he provides another proven player alongside a bunch of proven players. I would say - if Boozer returns to the court sometime soon and by December 15 appears to have regained his step, it's worth it.
Plus, Taj Gibson is having himself a pretty good year in Chicago...