Here is a pointer to the video of a live uClinux session running on the Freescale Kinetis K70:
Linux (uClinux) runs just beatifully on this device. Using 'dhrystone', we get about 50% performance we get on a 250Mhz Freescale PowerPC box. Fast boot-up, lots of RAM (the TWR-K70 module provides 128MB of RAM and 256MB of NAND Flash), networking, JFFS2, framebuffer, SSH, HTTPD, Qt/E - all this runs just fine on K70. Overall user experience is your regular "embedded Linux" on an MMU-full microprocessor.