The Staten Island DMV is like 4 miles from the NJ/NY border. I left Princeton around 9:45 a.m. and arrived back around 12:20 p.m. Most of that time was spent in transit and very little waiting at the DMV.
All in all, it was a pretty painless experience...except for the $170 I had to spend on license, registration, gas and tolls.
But, the point is, it's done!