It's not that it's TV-capable, but how so and what that actually means (it's more than signal processing...). It's not that the device can see, hear and speak to you, but how so and what that actually means (there is no predetermined limit to what you can do with it - as programmers and users alike).
I agree that not all is known about the device yet, but we do know that it comes with IR blasters, and we know that those suck from 20 years of experience. Sure, HDMI-CEC would cure those ills, but we also know that cable companies suck at those sorts of things. We also know that there's no DVR functionality, so.. yeah.
I agree that it's about what it all means, in the end, but judging from the things we know at this point, it means that absolutely nothing will change in terms of cable TV.