I've been there last July.

I've been there last July.
They had an anniversary exhibition for the Walkman, which was very nostalgic and had some interactive features.
The Sony Park itself is a great place to look at current camera innovations and try out some of the best devices that Sony has to offer.

It's not very big, but the entrance is free, so if you're around Ginza it a nice place to check out.

Because of its size and location in one of the most expensive shopping destinations in Tokyo I would not recommend it to everybody, because if you do not intend to shop in the high fashion stores located in ginza, the trip is probably not worth it.