"...There's no way that DBS will be able to match what cable can do for OnDemand programming...."
Of course they can- via IPTV. When the ViP series hooks up to your broadband internet connection, you'll be able to get what you want. The catalog for Dish and DirecTV will likely be as large as for cable. And ITVN has shown that using IPTV technology you can get real time SD of high quality today. If your broadband is not fast enough and you order an HD program, you may have to wait for that download to complete. Is cable providing HD on demand now?
How much downstream bandwidth are you going to need to download a HD program, more then what's available to the majority of folks now?
Sorry, OnDemand means I want to watch it now, not request it now and come back in a couple of hours and watch it. Yea, for SD it might be OK, assuming that you have something faster then a 768Kbps DSL connection, but for HD viewers it isn't going to fly.