So the Red Sox won't be trading for JJ Hardy, despite my advice. Instead Hardy is headed to Minnesota in exchange for Carlos Gomez. I think Minnesota won this trade, as Hardy is a much better offensive player and they're both exceptional defenders. That said, it does make a lot of sense for both teams - Gomez was clearly the odd man out down the stretch for the Twins this year and shotstop has been a problem for several years. The Brewers needed a starting centerfielder with Mike Cameron slated to leave as a free agent and JJ Hardy was expendable (and expensive) thanks to the emergence of Alcides Escobar. The general consensus is that the Brewers will use the money they've freed up to pursue starting pitching.
I'm not a huge Carlos Gomez fan, as his OBP is preposterously bad (career high is .297) and he doesn't really have any power. The key to making this trade work for the Brewers is that Gomez still has upside, he was the top prospect in the Johan Santana deal after all, will be under team control for an additional 4 years (versus two for Hardy), and will only be 24 next season.
According to Tony Massarotti the Red Sox were interested in Hardy, but the Brewers requested Clay Buchholz or Daniel Bard. The Sox counter off of Michael Bowden wasn't enough. The Brewers were between a rock and a hard place with no great centerfielders hitting free agency and the cost of starting pitching, but at least they've addressed one issue with the trade.