With the availability of online video growing steadily there's a clear oppurtunity for cable providers who also provide broadband internet service to branch out into the online market. You could argue that competition from services like Verizon's FiOS and AT&T's U-verse, combined with services like Netflix and iTunes, would make such a move a high priority simply to stay competitive.
At the same time, ISPs have to be careful about how they implement services that might compete with other activity on their network. Comcast executives have suggested in the past that P2P traffic is already significant enough to clog their network. In order for streaming video to be successful it would presumably need to be guaranteed a certain amount of that bandwidth during the same peak hours it's currently in short supply.
The FCC has sent a clear signal that they don't consider filtering specific applications to be a legitimate network management technique. On the other side of the equation giving preferential treatment to an application in which the ISP has a financial interest would almost certainly lead to not just FCC action, but also Net Neutrality legislation from Congress.