Hmm...for some reason I was always under the impression that elite pitchers allowed fewer than a baserunner per inning. Oh well, I hope he continues to develop.
Nieve is worth watching. On the hitting side you have Iorg (of), Manzella (ss) and Einertson (of) in AA. Although at this time I don't think any of them project as anything more than mlb backups. As Buck mentioned Cusick in Low A is worth keeping an eye on. Not a lot there and no "can't miss" prospects, but there are a few interesting arms in the upper minors. There is also the draft in a month. The astros have the #10 pick and 5 total picks in the first ~110 selections
Josh Flores would be on that list, but he tore up his knee in a freak offseason accident (slipped/tripped on a curb). Colin Delome has shown a bunch of power, but is struggling with making contact, lot of K's & a low BA. He's another to watch.
It's good that that Cusick guy plays 2B. Because as it stands right now, 2B & 3B are probably the only two positions where a prospect wouldn't potentially have some serious major league talent holding them back from the majors or starting. Outfield (unless Bourn craps out), 1B, SS and catcher are likely going to be set for at least another couple years.