All of the geniuses on the internet who despise Calderon and endlessly rant about how horrible he is at defense and how he doesn't get "real" assists and how he dribbles out the clock will be the first guys complaining next year that we desperately need a veteran, backup PG for Lowry.
Yeah, Calderon isn't a perfect player but no one this team has played harder than he has since he's been here despite the fact that Colangelo tries to replace him or trade him every year.
As much as I love having Calderon as a Raptor, I think it would be in both the team's and his best interest to trade him at the deadline, unless the Raps are looking as though they are securely in the playoffs.
A trade would bring back something for an expiring contract; anything is positive, in terms of asset management. Calderon could have the opportunity to 'chase a ring' with a playoff team. I would hope that BC would still turn around and attempt to sign him next offseason, to be Lowry's backup PG for the next couple years at a much reduced rate (2 years + 2 team option years, for $4-5M per season).
Best of both worlds and not totally unrealistic either.