End of the day we still need interfaces for uncompressed video, simply because encoding video + sending it over a low-bandwidth interface + decoding a video adds latency. 30ms of input (e.g. mouse) to video latency can make your life miserable.
I just wish we could replace the HDMI with the DP, it's slowly coming to the higher end TVs. But our devices (consoles, AVR...) wont change.