Seems like a reasonable trade to me... Not a steal in either direction.
Pronman mentioned that Clendening and Forsling are similar players, with Clendening being a slightly better player (I assume based on future projections). However, Clendening needs to play soon.
If Forsling has a typical trajectory he probably ends up as a slightly inferior version of Clendening. However, there's both more upside and downside with him, and of course there's a risk that he continues his strong trajectory over the past year and ends up as a better player.
Of course, it was Forsling's performance this year (along with Chicago's acquisition of Pokka) that made the deal viable. In July 2014, we never would have been able to get Clendening for Forsling.