I hope Danny trades him this summer. His stock is high and the C's need to get younger. If I were Danny I'd be calling Donnie Walsh. He is likely to blow up the Knicks and good players could be had for a pro's pro like Ray.
My trade proposal:
Ray
Perk
Scalabrine
for
Curry
Crawford
Jerome James
I think Curry is an upgrade over Perk (not defensively, but overall), Crawford is close to Ray plus can handle backup pg (and younger) , and James gives us a backup center. 
Heck Chief, this is the kind of trade that only Isiah Thomas would do... if he was the Celtics GM! Curry is a very fat man that gives the opponent twice whatever he scores, Crawful is a ballhog who can score, but very inefficiently, in very bad teams and Jerome James can't play anymore.
Going to the point: I think your reasoning is flawed when you say that "the C's need to get younger". At this moment, we don't. We just need to get better. I have no problems in trading anyone, including starters. But this offseason, only for better value. I'd trade Rondo for Paul, Ray for Wade, Paul for LeBron, Garnett for.. I don't know... Duncan, Howard. Next season we can reevaluate the situation.