I don't understand the outrage at all. There's no space for him at the moment, sad story but "crap" happens.
We have 11 players currently in our roster. Then we have Big Baby, that's 12. We plan to add another PF/C (Rasheed)... that's 13. We plan to add another SF (Ross, Hill, Barnes, etc.), that's 14. We are probably looking for another PG (Hudson, Marbury, etc.). That's 15.
Where does Powe and his massive injury fit at the moment? Nowhere. We could probably cur Pruitt, but it won't be to add an injured player... who knows, maybe he starts playing better. You can't make Pruitt the victim here, he deserves the chance to make the roster.
Before this happened, there were tons of speculations that this coming FA season, the Celtics will have to choose between Baby and Powe... by the majority this was an accepted turn of events, well we chose one. Too bad Powe is injured, but we're not a charity here.