At this point, I'm seriously thinking that all the future machines I build will be SFF. The first machine I put together was in a giant Addtronics 8500. It was nice to have all that room for my first build experience, but now that I know what I'm doing there's no reason to put up with such a noisy behemoth. I would use this for primary and secondary machines, and for computers I built for my parents.
Like others, I think an nForce2-based mobo would be much more desirable. Assuming no (major) issues are found with nForce2, I would buy the Shuttle nForce2 SSF components immediately. Two, actually. One for myself and one for my parents.
I would also like to see other mobo options, such as i845 and i850e, for people who want to stick with Intel chips. Of course, if NVIDIA ever does a P4 version of the nForce2, well, that would be the best of both worlds.
Continuting to offer (and update) the 2 PCI versions is important, *especially* in an nForce2 (yes, I appear to be harping on that) version where the integrated video could be more than acceptable for many peoples' needs.
A (modestly? significantly?) more expensive "high end" version of each mobo, with integrated SCSI, Serial ATA (until it becomes standard, in which case it should be in the "base" model), and 802.11 wireless would be fantastic.
Personally, I *love* how the new Shuttle looks. But SFF PCs definitely have the opportunity to go for iMac-esque popularity based on style, so it might be good to offer various case design/color options.
Seriously, these Shuttle SFFs are the coolest thing ever. Keep up the good work!