If it kills the C300 then it must also kill their own PMW3 which is just getting off the ground, so I doubt it. My guess is that it will be competition for the Canon Cinema-DSLR, and nothing more.
When I first read this, I thought you nailed it. However, it's a rough world out there and things are changing at Sony.
“Sony’s high-quality, advanced products for business use can help our consumer unit lead the market,” Hirai said today. “We will speed up development of products and promote cooperation.”