The question is wether your player or your display device does the "upscaling" better. I have a projector that's native resolution is 720p. It does a good job with upscaling the signal from a standard DVD from 480p. But when I fed it a 1080i signal from a Blu-ray player, it looked horrible. It didn't do a good job scaling the 1080i signal down to 720p. I tried telling the player to output a 720p signal to feed the projector it's native signal (so it didn't have to modify it in any way) and it looked fabulous.
At least in the receiver world, the term 'upconvert' refers to a receiver being capable of converting video from a composite/S-video/component connected source to HDMI or component, so you can just connect one video cable from your receiver to your TV display.
