Well then how did Namco do it on their UStream?They have the official hardware so probably they have the 'official exploit' with them which people don't have yet. You can do it with any display outputting hardware, just not readily available to the public.
It's the same as how they can stream PSPDX smoothly WITHOUT using the RemoteJoyLite plugin (because RJL is not strong enough to handle Taiko without lag)
I really think there's an external hardware involved there that isn't part of the cabinet.