They go on to explain a lot more and showcase more games being played.
They also tell you towards the end of the video during questions that its a North American market only right now. If you are on the east cost, you cannot play with west coast players until there is a central server location. Overall they have a lot more work ahead of them then they make it seem.
What I think will be great is if the service works anyone with a mac or an old laptop can play quality games without the hardware normally needed. So its interesting at least to see something like this progress.