From Lance McAlister I guess, I can't track it down any better than that:
Making the rounds in the MLB rumor mill......Dunn to Brewers for Matt Wise, Tony Gwynn Jr and an infield prospect being discussed.
The only two infield prospects on the BA top 10 for the Brewers this year (apart from Ryan Braun who's not really a prospect any more) are Alcides Escobar and Mat Gamel. They were the Brewers 9th and 10th best prospects, and neither seems to be anything to get terrible excited about. Gamel has put up decent numbers, but nothing earth shattering, and Escobar doesn't seem to be able to hit.
Gwynn is a guy who's supposedly a good defensive center fielder, but he has zero power. Might put up a decent batting average and on base percentage though. Matt Wise seems to be a solid reliever, but I just can't help but cringe at this point whenever Krivsky tries to bring in relief help.
I have a hard time believing this is anything more than rumor but it's really hard to tell. I wouldn't be a fan of a deal like this, but there are probably worse ways to go.