While driving by I've seen a few people skating there since we got the last snow. Not sure if some parts are snow covered or not.
Penn and Drexel both have tons of spots you'll recognize, but in general you should keep moving rather than session a spot.
To get to Paines from Penn, take the Schuylkill River trail on the Center City side, following the trail north will take you right to the park. If you enter from South Street bridge there's a fun ramp to skate down.