The Marlins fan site "Strip Club With Stanton" is decidedly NSFW (not safe for work), so many thanks are due to Phillies fan site "Zoo With Roy" for posting what may or may not be the new Marlins logo.
The Marlins are moving to a new ballpark next season and are changing their official name from the Florida Marlins to the Miami Marlins. Usually, such moves come with a uniform change.
Sometimes those changes are drastic. If this indeed is the new logo and color scheme, this change (seen below) is more than drastic.
The first thing that came to mind when I saw this logo was this Pink Floyd Dark Side of the Moon image.