Hart is in the final year of his 3 year deal and is set to earn $10M in 2013.
I can't see the Brewers trading Hart away for a low-mid level prospect. And I can't see the Mets trading a MLB ready prospect for Hart for a one year rental, or offering the kind of contract extension he will surely be looking for.
In other words... don't hold your breath on Corey Hart being a Met.
So if the Mets and Brewers are talking... hopefully it's about Jonathan Lucroy.