I had never heard of Stu Pomeranz before I saw him pitch for the Orioles in Spring Training this year. I came away relatively impressed, thinking Pomeranz would be able to contribute to the O's bullpen at some point during the season.
Injuries kept him out for much of the season, but Pomeranz did get into three games in Baltimore in May, pitching 6 innings with 3 K's, a walk, and 7 hits (including a two-run home run) allowed. His minor league numbers - split between Double-A and Triple-A - were slightly more impressive; 23.1 IP, and 35 strike-outs to just 3 walks. And a 0.00 ERA.
A tall guy who averaged 94 mph with his fastball in the Majors, Pomeranz also got a little bit of sink on some of his heaters which helped him keep the ball on the ground pretty well (59% groundball rate). The curve doesn't seem like a knockout offering, but it isn't the worst complement to the fastball (it can at least make the latter look better).
Already 27 years old, there's probably not much upside left with Pomeranz. I certainly wouldn't feel less comfortable going to him in the middle innings than to Kevin Gregg though, and if he sticks around with the O's for 2013 I wouldn't be surprised if he did a fine job in middle relief for the team.