If Kenny Williams could have gotten Cabrera or any other competent shortstop for Contreras, I have no doubt he would have done that instead of Garland. If Cabrera is extended, it's an okay deal. If he's not, I think it's a pretty bad deal.
If you believe Joe Cowley of the Sun-Times, it sounds like Torii Hunter will be a member of the White Sox within a week. That would leave LF in order for the Sox to find a leadoff hitter. If they're able to do that, perhaps by signing Shannon Stewart, the lineup wouldn't look too shabby.
That bullpen, on the other hand...
I wouldn't be surprised to see Crede moved for bullpen help, although I don't know how much of a return he'll bring with his back injury.