Honestly, I think Nintendo wanted to release just enough information to pique people's interest and get them to think about how it could be used before demonstrating it. There are hundreds of question that people want answered that relate to how well it works, how many games will use it, how Nintendo will package it, how it actually works, and so on ...
In other words, I don't think Nintendo announced this to impact Sony/Microsoft as much as they announced this to get people more involved with what was going to happen at Nintendo's keynote.







