The company says Clover Trail is a Windows 8 chip, they didn't really go into the details why Linux won't be supported but what it comes down to is that there's a lot of software work to be done, and that Intel isn't willing to do it.
The Inquirer reports Intel went to great lengths to highlight the new P-states and C-states that can shut down cores in the processor to save battery life. There's nothing prevent Clover Trail based devices from running Linux, but without support for the new power states the battery life will be much poorer than on Windows 8.
The decision not to support Linux may be an issue for the tablet market where most devices run the Linux-based Android and the Unix BSD based iOS. The move is thus seen as (unintentional?) support to help get Microsoft's Windows 8 operating system gain a foothold in the tablet market.