Not going to happen. Linux would need some changes and DRM support for CableCard. Plus they would have to get it certified. However, Broadcom devices run Linux and they're certified but they're embedded STB's that run some mixture of proprietary and Open Source software.
Actually they should reverse engineer a linux STB that uses a BCM chip. They might be able to work it out. Though mythtv and other Linux HTPC software developers have no interest in adding CC support.