Did you work at Onlive or something? I was always curious what their protocol was doing. I never bothered to look, because I figured it would take a while to figure out what I was looking at.
No it wasn't Onlive. The company that went public was Riverbed and they used their custom TCP between their appliances. My current company (which I founded) is PacketZoom and our custom protocol (built on top of UDP) communicates between our SDK in the mobile app and our servers distributed around the world.
We use Riverbeds on either side of our sat shots here in Antarctica. Work fairly well for the most part. I didn't know they were running a custom TCP implementation in between the end devices.