Well, If anything live TV related is announced, I expect it to be with TWC, since they seem to be very progressive on the matter (see TWC TV for Roku). However, their current offering still is merely a "bonus" service for normal cable box based customers. Roku may be fine with this, but I expect Apple to demand users be able to subscribe via iTunes just like with Netflix and Hulu Plus. I also think they will have their own Apple-designed interface and features, with TWC merely as a backend. That way, if other providers sign on later the user experience will be very similar.
I believe this is all inevitable, but might still be years away.
I don't think Apple will let individual provider apps on the Apple TV (CW, TWC TV). Yes, I know Hulu Plus is technically that, but I think a future solution will involve unification and not fragmentation. A developer free-for-all in the TV space could be bad for user experience, which Apple will want to completely control.
I would prefer Apple to make deals with the content creators rather than the distributors. The only benefit I can hope for if a deal is struck with a distributor like TWC is that they can offer that service nationally rather than keep it restricted to TWC geographical footprint. Increased competition is good for consumers and a larger potential customer pool would be good for any distributor with less overhead than a conventional cable plant.
In the mean time, I'll keep dreaming and will let you guys know when the pigs start flying.