i think that ATI is proving that they CAN make decent chipsets, but i don't think the Xpress 200 is quite there yet. The basic design is fine, and there are some cool things, like good overclocking flexibility and a really neat option to use both integrated and descrete graphics for different displays, but they really are behind on all the extras. The lack of ANY cool new features, like integrated LAN, HD-Audio, SATA-II, NCQ, hardware firewall, standardized overclocking tools like ntune, is just not gonna cut it for DIYers looking for a solid platform. Sure, you can't put everything on a mobo and fit it into an ATX form factor, but you can't very well offer NOTHING other than cool integrated video and decent performance. That's why the board is being adopted by mobo makers mainly for low end/HTPC use. In fact, the only currently available one is a micro ATX MSI board, and it sucks. No LAN, no PCIe x1 slots, no overclocking options, no frills whatsoever, yet it costs like $180 right now, whereas i paid $119 for my Chaintech VNF4/Ultra mobo, which is ten times better in features.
Still, i think ATI has passed a big hurdle in bringing competitive performance and stability to the table. If they can just focus on a better feature set (after all, their competition, the nforce4, has everything and the kitchen sink), i think they can make some serious inroads into the mobo market. Till then, i wouldn't recommend the boards to anyone but OEMs or those looking for a cheap, low end PC or HTPC with PCIe graphics.