Late Wednesday evening, Jim Bowden tweeted that Edwin Jackson was getting closer to being a Cub:

Cubs now the front runner for Edwin Jackson as negotiations continue with both Cubs and Rangers..4 yrs and approx 52 m is ball park #source

— JIM BOWDEN (@JimBowdenESPNxm) December 20, 2012

Bowden's been wrong before. However, the same report was tweeted early Thursday by ESPN's Buster Olney:

The Cubs have made strong progress on a four-year, $52 million deal with Edwin Jackson.

— Buster Olney (@Buster_ESPN) December 20, 2012

Seeing the same report, with identical years and dollar figures, from two national reporters, gives it more credence in my view. Personally, I think four years is a bit too long for a pitcher like Jackson, who has been with five teams in the last four years (although, to be fair, much of that movement was not his choice, as he was traded three times); I'd feel more comfortable with this kind of deal if the Cubs would make the fourth year a vesting option (and maybe they will).

Signing Jackson, along with the reported signing of Carlos Villanueva earlier Wednesday, would give the Cubs significant depth for starting pitching, as well as another bullpen option in Villanueva. The price seems reasonable. I'll update later Thursday if there's any further information.