The machine arrived today. It seems pretty sweet. Ghostscript compile is down to 53s. Fitz rendering of the tiger is 130ms, but some of that is debug overhead. I think I'm going to like this machine.
The only serious hitch so far seems to be on-board Ethernet, which gets stuck. Popping in a Tulip PCI board fixes that.
The Matrox G550 can handily drive the monitor at 2048x1536, or around 150 dpi. It looks surprisingly good, I think in large part to the quality of the Matrox card. I think I might stay with this resolution a while. Obviously, most default fonts are too tiny, but I can easily configure the ones I really care about.
testrgb speed is 30.5 Mpix/s in 24-bit. This is pretty good, but I was hoping for better. I'm not sure I have everything tuned yet. For one, this is XFree86 4.1.0, and 4.2.0 is now out. Incidentally, setting AGP to 4x makes no noticeable difference. I'm not surprised, but in theory it should. testrgb is very bandwidth-intensive, which is what AGP is all about.
rkrishnan: you're right of course, that real Internet telephony is untrivial. But in talking about D/A's, my main point was that the same basic platform could also do CD-quality audio, which would make it much more interesting to "enthusiasts", as opposed to corporate customers.
I think it's inevitable that all these kinds of products will come out over the coming months.