If you have both in one room (or even another part of the house), you could run another set of video cables, split it, etc.. when comming out of the box.. BUT.. as stated, BOTH would be playing the same stuff, watching the same shows, etc.
If you want to be able to watch stuff that is recorded on the PVR on another tv in another room, but still have regular tv watching, etc separate, then again Tmothy12 is correct. You will need a 4642 HD box in the other room. You can then have the whole home PVR setup installed, which will allow playback from the PVR, from that other box.