Re: DishDVR 921 - Look for at least a limited introduction in early November (yay!). I've been eagerly awaiting this product as well. BTW, the 921 has 1 ATSC tuner as well, and can even record ATSC broadcasts. Supposedly they will be integrated with the guide to some extent as well.
Given that, I'm not sure what the need for an NTSC tuner is. My area isn't exactly top on the HDTV list, but all the local stations are now, or will very soon be, broadcasting an ATSC signal. That is what I meant by NTSC being soon dead. Many people will still have NTSC display devices, and alot of stations will still be broadcasting an NTSC signal. But if I had the choice between using the ATSC or NTSC (even processed by the best transcoder money can buy) signal I'd definitely choose ATSC, especially when I was concerned about using DVI as interface to the display.
At least for me the 921 will take over all "TV" duties, no need for any other tuners. Let's hope the silly thing works
I'm also puzzled by your desire to use both a DVD player and an HTPC. You could use the HTPC for your DVD duties as well, unless you wanted to have a DVD changer of some form. But then the only other thing I can imagine using the HTPC for is playing games on a big screen, not something a G4 cube would excel at... Just curious here
I have to agree with your D-VHS choice, that does make at least 3 sources to deal with (TV, DVD, and D-VHS). I wonder if D-VHS players with DVI output would output regular VHS and S-VHS tapes via DVI? That require a built in transcoder, so probably only on the higher end models. In any event transcoding VHS to HD-DVI is basically useless except for convenience, you know what they say about polishing a turd... Might be better than via composite, but still nowhere near even standard DVD and much more expensive.
Signal generator: would love to have one, but certainly can't justify the cost for myself... Avia will have to suffice for me at least

I wonder if anyone will put out a test D-VHS tape? Would certainly be nice.
As for Sony.... eh, basically fits the pattern. As soon as they figure out they need to upconvert composite and S-Video to component, they come out with DVI switching, but forget to transcode to DVI! There goes that supposed convenience right out the window... I think the same thing happened when composite to S-video upconversion started to appear, they added non-upconverted component at the same time. I wonder if convenience will ever catch up to technology... of course they also just figured out that they need at least 3:1 component switching... Only a year or two too late for most people who would care...
-- Dave