Sony released a video moments ago titled, "Evolution of PlayStation - The Beginning". It takes a look back at the history of the original PlayStation and the DualShock Controller. I'm going to assume along with the top rated comment on the video that this is going to be a small series of videos.
Starting with today being the PlayStation as we saw. Then tomorrow, the PlayStation 2, then PSP, then PlayStation 3, then PSVita, ending on the 20th. This date being the big announcement or unveil of the next-gen PlayStation.