As a sidelight to the major trade and free agency rumors, the Winter Meetings are host to the Rule V draft, where teams can draft the proverbial Quad-A players who can't break out in the majors, but have enough minor-league service time and aren't protected by the 40-man roster.
The big news is that Jim Hendry may be making a Rule V selection for the Cubs; he's understandably not sharing who or even what position he's looking at, because the Cubs have shoddy draft position. But it's something to be watchful of.
As far as speculating... I'm nowhere near well versed enough to offer credible suggestions. BP's Bryan Smith does have a few ideas. (Subscriber only.) He says there's good pitching depth, but only two hitters getting any buzz: Brian Barton, who has shown good plate discipline and takes a great deal of walks, but doesn't hit for as much power as one might like in an outfielder; and Chris Lubanski, who has more power, less walks, and only plays left field. He also says the Cubs could lose LOOGY Geoff Jones.
Arizona Phil of TCR, as always, has the best scoop on these sort of transactional things; he lists 45 players who are exposed to the Rule V draft from the organization.
Guys whose names you might recognize:
If you asked me, Kroeger is the most likely of those guys to go.