Yeah, I remember seeing that. Just wanted to mention the 780G in reference to the wish for a 780G in mini-ITX form.
Seems prices are currently only much lower if you either go with an Atom board (CPU+MB for less than a board -- though the performance won't be anything near a "normal" AM2/775 CPU) or a GF7000-series board.
Also, while you can certainly debate the merits/value of mATX vs mITX, the simple fact of the latter's 6.5" square size against the 10" square of the former is undeniable. It's really where mainstream computing is going. I think a lot of people are willing to pay a bit of a premium for the small size, even $50 is not big in the context of a whole system. And mITX prices will keep declining.
I'd personally love to convert my Linux server over to something smaller. I've currently got a P182 housing the micro-ATX system, optical drive, and single hard drive, which is overkill (but the price/performance was right and I love the P180 I've got housing the main system), especially since we have it "hidden" in an open-backed cabinet and the P182 is a bit tall and deep to truly "fit". (Many thanks, by the way, for the work you did with Antec on the P180. Though I'm not as sensitive as many here to noise level, I much prefer whooshing to whining and being able to run as cool and quietly, with as little "extra effort", as possible.)
Since I've got a very small server in a very large case, a mini-ITX setup would be great (case just large enough to hold the MB and drives and use a PicoPSU), it's just a little much currently to be worth it to me. But then again, my system's out of the way and running fine, so it can wait until the prices trend downwards a bit more (though that hasn't stopped me from looking at options). For someone else, though, it may be more than worth the premium, especially if they're bringing up a new system or moving an existing system to a new location where it doesn't fit as well. With a small mini-ITX case, there's not many places you can't fit a computer anymore, which is pretty cool. I like the examples I've seen where a small case is mounted on the back of a monitor; all-in-one convenience, but with greater flexibility in changing individual parts.
At least the situation's better than the last time I was looking at converting my server over to mini-ITX form, when it was pretty well impossible to find much of anything in the mainstream channels. They're out there now, prices aren't horrible, and hopefully over the next year or so we'll see a much larger selection at even better prices, especially since there's at least the Eee Box out in the wild (and netbooks really seemed to explode after the Eee PC came out, so maybe Asus will be helping the nettop market move, too).