Enjoy the 332 flight. Its a nice ride. Do be aware that when US is using an A330 domestically, boarding starts either 40 or 45 minutes prior to scheduled departure (as opposed to 30 for non widebody aircraft).

Your 757 flight is more than likely an "east" aircraft with 12 Envoy class seats that often will continue on to Europe after you land in PHL.

Easiest way to tell if its a V2 or V3 757 is to see if there are two full rows of coach behind first class and forward of the 2L door or one row on the left side and two rows on the right.