Fellow FanHouser Ed Price is reporting that a trade is done. Will update with destination and return as word leaks out.
UPDATE: DK at the PG says speculation at PNC says the elder LaRoche is going to the Giants, though it's currently uncomfired. The PBC is crashing, though.
MORE OFFICIAL UPDATE (12:18): The Post-Gazette's website sucks, but DK just said on Twitter that LaRoche is going to Boston. Ed Price updated right before that to say that the Sox and Pirates had been discussing a deal, so it looks like another trade with the Red Sox.
SPECULATIVE UPDATE (1:07): People are asking me on Twitter if the return is Yeiper Castillo + PTBNL. I have no idea if that's actual the return, but I wouldn't be surprised if the return is something similar to that. Meanwhile, DK says that speculation (again unconfirmed) among scouts (same link as before to the PBC) is that Jack Wilson may be involved in something today as well.
ACTUAL UPDATE (1:12): WEEI in Boston says Argenis Diaz (SS) and Hunter Strickland (RHP) are the return from Boston.
FINAL (FOR NOW) UPDATE (1:44): I'll do a full post when I get home this evening, but this return strikes me as about right for LaRoche. He's going to be a free agent this off-season no matter what (no one is going to risk offering him arbitration and having him accept the offer) and to get a prospect with a good glove at shortstop (which is what Diaz is; all glove no bat) and a young pitcher with some potential is about as much as we can ask in return for a guy that's going to be a bit player in Boston for two months.