My preference would be to retain him, but as you say there is a counter argument. Our forward line struggles primarily for a lack of mobility, and the need for players who are strong at ground level. Dawes and Cloke together means we're pretty heavy inside 50m and we really need someone who can crumb, especially if those two aren't able to take a mark as happened for roughly half of season 2012. Krakouer is that guy when healthy, and added a new dimension to our forward line once he returned. Finding a successor to Krak should be a drafting priority.
If we were to trade Dawes out, it would be an indication that we believe Lynch can fill the role, probably in combination with Paine, for the next couple of years until Lynch is done and dusted. It would also be an indication that we're happy with the guys we've got coming through in Gault, Stewart and maybe even Moore in a couple of years (again, looking forward to around the time Lynch will be hanging up the boots). It's a gamble as it leaves us with little depth, but it might secure us a pick with which we can address our other areas of weakness.