Maybe I'll get the AGP PCI board. Downside is no Vista compatibility and crummy support. It
is cheap! I suppose the potential for conflicts with the MDP are much reduced, as well. Thing is, the nForce 4, PCI-E board does have AGP compatibility of sorts with an AGR slot, that probably will work to some degree (!) with my dual-DVI BFG 6600 GT AGP card. It's said to be wired to the PCI bus, and will not give true AGP features. Also, the vid card has to be able to tolerate 3.3v, which I don't know about.
Prices of PCI-E video cards are dropping, and I can get the PCI-E version of my current video card for around $60 after MIR at Newegg.
DC says that MSI K8N Neo4 Platinum, is compatible, but that's a different board than the Nforce 4 board I'm considering here. I believe it's 939, for one, plus it has a 3rd PCI-E connection and one more PCI slot, I believe.
So, the issue isn't that the MyHD doesn't work with PCI-E video cards, then?
As far as that Asus MB goes, my PP supports my printer right now (HP4M), but I have a Jetdirect network card which I haven't installed yet in the printer, which should enable me to forego using the PP altogether, if I'm not mistaken. Can connect the printer directly to my router for access to all my PCs.
I guess the simplest upgrade right now (other than shopping for a used Mobile Barton and dropping it in my current system and overclocking it) is just to get that cheap 754 AGP 5xPCI board and figure if and when I want to run Vista on my desktop I'll be shopping again for computer parts!

Meantime, my laptop does support Vista, but I'll have to apply for my Vista upgrade to get it.