My receiver does not have 1080p upconconversion. Will I need to have separate cables for non-HDMI sources? Will the Samsung PN50B650 tv upconvert them for me?

Plasmas are fixed pixel displays. They will automatically scale all sources to their native resolution (1080p in this case).

Plasmas are fixed pixel displays. They will automatically scale all sources to their native resolution (1080p in this case).

So you mean it will improve the quality (like upconversion of dvd's), not just "readjust" the resolution to 1080p?

It's not going to create detail that isn't there, so there will be no improvement in quality in that respect. From what I gather, upconverting 'quality' is relative, as in that receiver upconverts to a better quality image than that tv- but neither of them takes an SD image and gives it HD quality.