About converting PPT to video of any sort, check this message board:
http://www.greenspun.com/bboard/q-an...?msg_id=006ZBn
currently, I am not sure of anything that can convert PPT to video in the true sense, especially if you have heavy animation within a particular slide. if you do not have heavy animation and it is a simple slide presentation, you can save each slide in a picture format and reassemble them into an MPG creator like TMPGEnc keeping in mind that normal video is 25 - 30 frames (slides) per second. You can also try a screen capture that allows you to configure the fps and save into avi, like CapturePad by VRTainment (
http://www.capturepad.com &
http://www.vrtainment.com). I also use an S-Video out from my computer to the S-Video in on my digital movie camera and record in tape player mode the playing of the PowerPoint. I then recapture the video with firewire. As far as extracting vocals from a music, it is not always going to work perfectly unless you purchase expensive software (unless someone corrects me on this.) But you might want to check dBPowerAMP (type it into Google) if you download the Power Pack DSP Plugins, there is an option to extract vocals, you must have the original cd with you.