Video routing
Atomic,
Do you already have all this gear, or are you considering the purchase?
If you are in the market for a receiver, you should consider one in the $3-400 range like the Yamaha RX-V659. It will provide video switching of all of your component sources, but not HDMI. Purchase a quality Oppo DVD player or maybe HD-DVD to take advantage of your new set when watching movies. Connect the DVD and other HDMI sources directly to the TV.
If you already have the new receiver, allow it to convert all video to HDMI and experiement with the upscaling feature. It might be slightly better than the scaling in your samsung TV.