idk where this CP3 to Boston rumor started (likely, in the forums) but there's been NO indication that this is something the C's are even considering.
Of all the trade chatter surrounding CP3, I have yet to hear Boston in the mix (all I've heard is Portland, NJ).
Fact of the matter is, unless CP3 comes out and says he wants to be traded, he's not leaving NO. They avoided the luxury tax by trading Mo Peterson and Cole Aldrich, so the urgency to move CP3 is not even as high as it was once thought to be.
Moral of the story: if anyone is really expecting the C's to nab CP3, you may be very disappointed.