I'd still roll the dice on Francisco Liriano, especially after his showing in the Winter League and the addition of Orlando Hudson and J.J. Hardy on defense. I suppose you could upgrade the entire pitching staff, even though none are heavy ground ball pitchers. (Nick Blackburn has the best rate, but even he's just at 1.26 GB:FB). Joe Nathan's still my No. 2 closer even with the offseason surgery. Pat Neshek apparently feels great and could again be an elite setup guy.
No idea what the Twins are doing at third base. Nick Punto can field and run, but can't hit, Brendan Harris can hit a little bit and Matt Tolbert - not sure what he's good at. Maybe Danny Valencia gets the call at some point. J.J. Hardy averaged 25 HR and .280 from 2007-2008, so he should at least earn whatever he costs after last year's disaster. He's still only 27.
Denard Span is still just 26 and has now done it two years in a row. Delmon Young is only 24 and could have a major breakout after a strong September and enough dedication to show up in shape at least. (For a player with a questionable work ethic, that might be more relevant).
I don't know how much Jim Thome has left in the tank, but someone in the OF will get hurt eventually, moving Jason Kubel there and Thome to DH. I have Thome even below Hafner, though.