The P2 camera records data to P2 cards, which record around 64 minutes of full HD footage. The cameras take 5x P2 cards in total, which can be swapped out and downloaded whilst on your shoot.
The P2 data can then be transferred to a standard portable hard drive through the P2 card reader and a laptop, giving near-instant access to the rushes. All the digitizing time is reduced and multiple copies of the P2 files can easily be made.
There are essentially two P2 Varicams - a full 2K HD resolution 1080 line P2 version (HPX3700) which will record variable frame rates up to 30P, and a 720 line P2 version HPX2700) which will shoot, as did the tape based Varicam, up to 60fps.