The terms of the deals aren't awful, but it is very hard to imagine it going through in this environment.
The Yankees are literally rolling in money, with Steinbrenner's adept creation of a local sports empire including the Yankees, Nets and Devils, and their inevitable morphing into a dedicated cable channel. There is no rationale for the city helping that club at all.
As for the Mets, their God-awful ballpark is usable, if unpleasant.