I like the first two responses!
However, I'd like to add one caviat, and that's that picture quality in regards to regular interlaced 230 line resolved satatlite feeds will depend on how your Plasma deals with the signal. When you're dealing with a signal that's changed from interlaced to progressive on these HD ready TV's, you often soften the picture for regular rez material, and add some artifacts! There's really no problem here with HD material or higher rez DVD 480 line stuff.
I've noticed this many many times, where the picture people expect on their expensive plasma isn't what they think(*or on their HD bigscreen for that matter) for regular program material.
I'd suggest getting a plasma that allows you to turn off the deinterlacing progressive scaler, and just play through interlaced from the signal. I think this offers a better picture mostly for lower rez junk.
Anyone have feed back here?