I think you would have to post your entire roster to see if this deal makes sense. I think that the deal is fairly even for the rest of this year, and that both guys are borderline in terms of their 2013 keeper prices. However, I almost never advise trading offense for pitching unless your offense can definitely sustain the loss. I think a lot of people underestimate the loss of a bat and overestimate the addition of a big game pitcher (even a true fantasy ace, which Haren is not). This usually spells disaster.
But if you post your entire roster, it will give a better picture in terms of your replacement value offensively for Freeman (Encarnacion replaces Freeman, but who replaces Encarnacion at UTIL as he is surely in your starting lineup). Also, what are the timetables of return on your guys who are injured, what other starters do you have, etc.
Also, a general idea of where you are in the standings (I assume this is roto by the description) may help figure out if the jump in points in the pitching categories will be worth your loss in offense.