jn and Skander,
Agreed. Hudson for Watson defensively is a great deal.
The problem is that means you really need to ship one of your point guards out. And, if it were me, I'd be looking at shipping out both Cassell *AND* Hudson.
If you could get Payton or some other starter-worthy point guard to sign, and then ship Cassell/Hudson out - say to Houston, who needs a point guard - for someone like Jim Jackson, you could make several upgrades and add depth.