Keith Law’s (Insider-only) article at ESPN breaks down the pieces:
A fifth-starter type with good command and deception but fringy stuff without a real knockout pitch. He's a particularly bad fit for Houston's ballpark as a left-handed fly ball pitcher who has had some trouble with right-handed hitters. He's also coming off a forearm strain that has ruined his 2010 season. Other than that, he's everything you could ask for in a pitcher.
A long-term project, a plus runner with a chance to be a plus defender all around at shortstop, but he is extremely raw at the plate and projects to have fringe-average power at best.
On Brett Wallace:
He's an advanced hitter who has been adequate in Triple-A this year but hasn't raked as I would have expected, given what a good hitter's park that is. However, he has an outstanding swing and controls the strike zone well, doesn't show the platoon split so common in left-handed hitting prospects and was just 23 in Triple-A. He's twice as valuable a prospect as Gose. Despite concerns over his lateral mobility, he's a capable first baseman who will hit for average, get on base and have enough power to be an above-average or better player there.