I went on the google website today to buy a nexus one and I was greeted with "Sorry, this item is temporarily not available". Is something going on with nexus one sales for T-Mobile through the google website.
From what I understand, there is a shortage of AMOLED displays (one reason the Droid Incredible has been backordered). The same thing happened with the ATT 3G version a week or two ago (it was unavailable for about a day). They're probably just waiting to get some more in stock.