This was mentioned yesterday, but I thought I would bring it up again.
Dwight Howard dominates NBA trade buzz but numerous others figure in talks - NBA - Sporting News
While there has been plenty of focus on Celtics point guard Rajon Rondo, sources indicate Allen has generated the most interest from contenders. He is a knock-down perimeter shooter and a veteran who can blend well with any team. Even at age 36, Allen is in great shape and, as a free agent after the season, an easy fit into a team’s books. The Celtics don’t want to trade Allen, but if they continue to slide and are offered a young piece or a draft pick, making a deal would be hard to resist.
The thing with trade value is that it is a double edged sword. The guys that would bring the most in return are the guys you would least like to part with. I'm of the opinion that Ray Allen has like 2 or 3 good years ahead of him in his current outside shooting threat role. He is a plug-n-play stretch the floor guy that could help any contender. Which is exactly why, if the Celtics are going to be contenders this season or for the next few, that he should be kept around if at all possible.
But I have to agree with the author, if the Celtics do decide to go in another direction, then trading Ray for first rounder or a young player with high upside would be a reasonable return. He's also the easiest to move considering his expiring contract and the fact that he makes "only" $10M (in comparison to KG's $21M).
I would very much like to see Ray retire as a Celtic, but I could see him being the first to go as well.