In a word, no. It's pretty desolate out there in EWR territory. But as others have said, trains into Manhattan come thick and fast -- so reliably that an expensive taxi really isn't worth it.

The QM2 sails from Brooklyn / Red Hook Terminal, not Manhattan, actually, and it's an area worth exploring with some nice hotels and restaurants. You might consider bolting straight through Manhattan on arrival and staying over there. Easy transfer at Penn Station to the F train for Brooklyn.