There have been a few moves involving first base this off-season which have really shifted the market. The Twins had a need at first base, but filled that when they moved Joe Mauer to the position full time. The Rangers acquired Prince Fielder from the Tigers, and Detroit moved Miguel Cabrera across the diamond to replace Fielder. Those two moves eliminated at least two teams from the free agent market, without removing any free agents.
As far as actual free agent signings, the Rockies recently filled their first base need with the addition of Justin Morneau. That takes another team off the market, without taking one of the top first base options away. Paul Konerko and Jose Abreu signed with the White Sox, so their first base position is covered.
Tim is the owner and editor in chief of Pirates Prospects. He started the site in January 2009, and turned it into his full time job during the 2011 season. Prior to starting Pirates Prospects, Tim worked with AccuScore.com, providing MLB, NHL, and NFL coverage to various national media outlets, including ESPN Insider, USA Today, Yahoo Sports, and the Wall Street Journal. He also writes the annual Prospect Guide, which is sold through the site. Tim lives in Bradenton, where he provides live coverage all year of Spring Training, mini camp, instructs, the Bradenton Marauders, and the GCL Pirates.