UPDATE: See this post for updated information on this. Apparently they aren’t ready yet.
Looks like Lenovo is now offering Core 2 Duo Thinkpad X60 Tablet PCs according to the product page .
There are four options on the page (note the substantial sales price difference) and the second, third, and fourth ones yield the Core 2 Duo option when you choose to configure your order
Thanks to GBM Forum member GuiX for being the eagle eye on this one.