The only reason I'm addressing this is that our good friends at Lookout Landing keep checking this site.
Here is the rumor du jour:
It is extremely doubtful that Willis is available, though it is true the Marlins would like to improve both positions, catcher and center field. Starting pitching is a bigger issue for the team this season than either of those positions. At the present time three of last year's starters are on the DL (Sanchez, Johnson and Nolasco) and two have recently been pitching with injuries (Willis and Olsen). The starting staff is being held together with duct tape and baling wire. Eventually the Marlins will have to address both the center field and the catcher situations. But it is very possible that the Marlins could improve both positions within a couple of years with players already in the organization.
The other thing is: the Marlins are trying to secure stadium funding and after two fire sales, trading Willis could possibly be a horrific P.R. move.
All of that said, I've been wrong before.