Simple answer no, ps3 will play cd, dvd and blu-rays. Going to have to buy a HD-DvD player, if you want to watch HD-DvD's.
No, but if you have a way to rip them to your hard drive they can be converted to BD format and play on a BD player and still be in high definition. All that you need is an HD DVD drive, HD AnyDVD, a standard DVDRW, and Ripbot264.