All of Sony's cameras have run Linux for years. It'd be interesting to find out what Tim Bird thinks about this, as he's managed Sony's embedded Linux development efforts in recent decades, and also a lot of industry-wide embedded Linux committee and event activities. Not sure what bits of Sony's stack are GPL'd, or if the hardware architectures are compatible (both likely ARM, but little-endian? big-endian? etc.) but perhaps some Sony software could be ported, giving a boost to those hoping to implement a full Linux-based software stack for Canon DSLRs. This might be a good place to start looking for usable software bits: http://oss.sony.net/Products/Linux/DI/category01.html