It's at http://online.wsj.com/article/SB122834809064877527.html
. Its somewhat discouraging title is "Scratch that Kindle Off Your List," referring to the scarcity of supply, which it traces to Oprah's endorsement. It has some interesting comments on the eBook industry in general as well as the Kindle.
(Full disclosure: I was interviewed for this article but my interview was not used. But it's still -- or maybe as a result! -- worth a read).