I think the problem is that VIA stated a very early availability, thinking it could beat the other guys to market with its K8T890. It then hit problems with its new VT8251 southbridge which was originally part of the K8T890 spec, and half of the product feature maps even feature it, even though they have now changed to use the VT8237 instead. Then, back in september, they announced the part, and immediately Abit put its AX8 on the board. Problems ensued, and as you can see, the parts still don't exist. Whether VIA thought it could make the deadline and had problems, or it just lied to gain mindshare from those who still thought it would be first to market, is unclear, but either way, they dropped the ball. However, all the other companies felt like they had to poise like they were ready to go, even if they were not, either. So basically, each company has had to spend most of this year pretending their chipsets were working and almost ready, when in fact none of them were, just so they wouldn't lose most of their sales, should a competitor release their solution first. It was basically a giant bluff, with the loser being all of us.
Anyways, I think the worst is finally behind us. Several mobo manufacturers all say that nForce4 Ultra and SLI boards will be out shortly, and for the most part, I believe them. Many manufacturers are taking preorders, and most even have ETAs in mid december. Of all the mobo makers, I hold the most faith in gigabyte, currently. They have shown that they can get boards out to lots of reviewers, and those boards perform better than any other boards I've seen, so I smell an upset of Gigabyte over Asus in this round of the mobo wars.