Joe Sheehan offers up some breakout candidates for 2008, and includes one of my favorite Rangers on the list:
Ian Kinsler: Starting with McLouth, we get into players who aren't quite as strong candidates. Kinsler made small improvements across the board in '07, hitting more fly balls, walking a bit more, stealing more bases at a better rate and playing better defense. Given a full season--Kinsler has missed 74 games in two seasons--he could put up Dan Uggla's numbers, with much better defense and a higher OBP.
Jump on the Kinsler bandwagon, while there's still time!