I think it's fair to assume that Jordan Lyles will be in the rotation by the start of next year, so he is technically no longer our top prospect.
Here's the way I see it:
10. J.D. Martinez- J.D. has been on and off in the minors this year, but mostly on. Most people in the FO expect him to be called up at the end of this year.
9. Tanner Bushue- Tanner's a wildcard for me. His inconsistency worries me, but his talent still tells me he can be a good player.
8. Austin Wates- I really like this guy. Problem is, I'm not sure we have room for him. I've been lobbying for both Pence and Bourn to be traded, but Ed Wade is currently pulling an Ed Wade. Hopefully Wates will have a spot in 2012 or 2013.
7. Adrian Houser- Adrian comes in with good tools, but he needs work in some areas. I expect him to be our #3, maybe even #2 of the future behind Folty and Lyles.
6. Jio Mier- Jio is just like Tanner. He had a pretty poor first year, but has bounced back in a big way this year. I'm still not convinced though, because he hasn't even been to AA yet.
5. Mike Foltynewicz- Folty is one of my favorite prospects. His big arm will give us a nice change of pace behind Lyles, assmung he's the future #2.
4. Jonathan Villar- I really, really like Villar. His tools are fantastic, and his defense could become elite. His bat has been streaky while in our system, but he's been called up to AA, and so far he's playing well there. He could be an Astro as early as July in 2012. His speed and decent pop make him a prototypcial #2 in the batting order. That would be welcomed, considering we've been shuffling around the #2 spot the entire season
3. Ariel Ovando- Ariel is a very exciting prospect. His high ceiling and raw power could give us a potential stud in 2014, assuming he pans out.
2. Delino DeShields Jr.- Delino has had a good year so far. He's hitting for some power, and he's stealing bases. With Villar due to come up around the same time as DeShields might, I imagine Delino would be the lead off guy.
1. George Springer- I'm very excited about adding George to our improving farm system. His athleticism gives him a very high ceiling. I imagine his ceiling would be a BA around .280, 30 or so homeruns, 30+ stolen bases, and 100+ RBIs. The Astros made a great pick here. All he needs to do is fix his swing a little bit, then he's good to go. Expect George to make a case for the 2012 roster, whether it's in May or June.
This farm system could get even better if we trade Bourn, and especially Pence. Not to mention the fact that Wandy has some good value right now.
But, Ed Wade will continue to be Ed Wade, and I can't blame Ed for being Ed. It's in his nature to be generally stupid in these types of situations.
EDIT: This list is based off of a prospect's ceiling. I probably did a poor job in ranking DeShields ahead of Ovando, but apparently Ovando is only 17 and he's got as high of a ceiling as anyone in this farm system, maybe even higher than Springer's. Springer is yet to sign with the team, but in an interview he said he will absolutely sign with us, and even though he has yet to see a pitch in the minors, he's probably got the most potential in our farm system, maybe excluding Ovando.