I think it would be cool if there were a team in Northern New Jersey.
This article here discusses the economic viability of the top ten places MLB could place a team, and you may be surprised to see that NJ is number one.
Now before you roll your eyes remember that Fred Wilpon is still obsessed with the 1950’s – when the Dodgers and Giants played every 10 minutes, and these days we’re supposed to believe that the Mets-Yankees series is the end all be all….so give it a few years and maybe Mets-Marlins could be fun.