Depending on what you use to do the encoding, a dual-core 3800+ could chop your encoding times in half. And the system will run smoothly while doing them, too.
Oh, and Adobe Premiere Elements 2.0 comes to mind, it's not too difficult to use IMHO and you could edit out the commercials with some timeline scrolling to locate them, a few clicks to split the video, and then just Delete And Close Gap. Premiere Elements will use both cores nicely.