Per Evan Grant and Jason Cole on Twitter, the two prospects sent by the Rangers to Chicago in the Ryan Dempster trade are Christian Villanueva and Kyle Hendricks. My initial reaction is that this is a significantly weaker package than I would have expected the Rangers to have to part with for Dempster, although Villanueva and Hendricks are both nice prospects.
Kyle Hendricks is a 22 year old righthanded pitcher who was an 8th round draft pick of the Rangers in 2011. He made the Northwest League top 20 prospect list last season, and has had a solid season with Myrtle Beach in the high-A Carolina League in 2012, putting up a 2.82 ERA with 112 strikeouts against just 15 walks and 8 homers in 130.2 innings pitched.
Christian Villanueva is a 21 year old third baseman who had a breakout year in 2011, putting up a .278/.338/.465 line for low-A Hickory while impressing with his glovework, and landing at #100 on the Baseball America pre-season top 100 prospect list. After a slow start to the 2012 campaign, he's heated up lately, and is currently sporting a .285/.356/.421 line for high-A Myrtle Beach.
While Hendricks and Villanueva are both nice prospects, I don't think either would be considered to be among the Rangers' top prospects, and they aren't huge ceiling guys. In addition, Villanueva's future in Texas was limited because of the presence of Adrian Beltre and Mike Olt ahead of him. Both guys were more part of the Rangers' prospect depth than they were elite types, and I'm pleasantly surprised that this was the extent of what the Rangers parted with to land Dempster.