The Inquirer's Charlie Demerjian has written an interesting article on the reasons behind Intel's chipset shortage. According to the article, Intel has been taking down third party manufacturers, and a poor planning which lead to a lack of capacity, so it all went a bit pear-shaped.
Basically what happened was it killed its so called friends, and for a while, that worked just fine. It left just enough wiggle room for the Taiwanese chipset makers to survive, but barely, and I mean barely. Intel made sure there was no money in chipsets unless it decreed that there would be, and since it can shut that pipe down on a whim in less time than it takes to get a chipset to market, the sane vendors ran for the door. No one else was dumb enough to enter the Intel chipset market, and this situation is likely to continue. They planned the killing, and, er, executed.