Former top prospect and recent headache (why oh why doesn't he pitch better?) Hayden Penn is out of the competition to make the O's rotation. Given the news, I don't think he's likely to make the bullpen either. Penn will instead be starting his year (in all likelihood) in Miami, pitching in some role for the Florida Marlins. That's one way to end the argument about whether he can become a major-league pitcher - make that someone else's problem.
In return, the O's get 24 year-old shortstop (though he's played second, third, and center also) Robert Andino. The guy can't hit (.201/.250/.299 in 144 career at bats) but he's supposed to be a a good defender (he hasn't played enough innings for UZR ratings to be at all valid 9though they are negative), but Tango's fan scouting reports has him as a bit above-average but not great).
CHONE projects him at .237/.296/.352, though he did hit at a .287/.356/.497 clip at Triple-A last year. Andino's out of options (as Penn was) and will make the team as the back-up shortstop.
I don't love the move, as I've always thought Penn could be a capable back-of-the-rotation starter (and better than Adam Eaton is at this stage), but it's not bad by any stretch. I never though it likely that Cesar Izturis could go play in 162 (or even 150 games) so having a guy who can actually play the position credibly is a plus. Really, the thing I like most about the move (and I do like it quite a bit) is that it means the team will go with only 12 pitchers instead of the 13 that had been generally discussed. There is absolutely no need for 13 pitchers - someone is going to be used very sparingly (even with this pitching staff) and that roster spot will just go to waste.