"I have not heard that TWC uses MPEG 4 at all. Where did you heard this? Last time there was a free preview of them they were in MPEG 2 in my region."
The HD iNDemand channels are only available in MPEG 4. I believe ESPN 3d is MPEG 4 as well.
actually that varies by market. Only the markets with GAME 1-9 HD and TEAM 1-9 HD have the MPEG4 versions all of the other areas that have GAME HD and or GAME HD and GAME 2 HD as well as TEAM HD are MPEG2. But ESPN 3D is MPEG4 nationwide and to be able to have ESPN 3D on your system you need to have digital simulcast with a DCX motorola box, Samsung 3260/3270 or higher, Cisco 4640HDC/8640HDC or higher.