Kovacevic is a great guy to have around at his current cap hit, he's fine on the 3rd pair and because he makes **** all it isn't a big deal if he sits in the press box for games.
The reason I would trade him this year or next would be because he'll get a big raise once he becomes a UFA and I don't want the Habs to be the ones to give him that increase.
GMs are obsessed with right shot defenceman with size, next summer some GMs will see a 27 year old 6'5" right handed shot D and overpay for him. The last couple offseasons we saw third pairing, RHD with size like Holl, Rutta, Lyubushkin, Schenn and Poolman get around $3M.