Nintendo has made formal announcement of tomorrow's Nintendo Direct broadcast, complete with an official site.
The official site says that the presentation will be delivered, like the first Nintendo Direct, by CEO Satoru Iwata. Also like the first Nintendo Direct, we'll be watching a recording. The session was filmed on the 19th.
In a message posted to Nintendo's official Twitter, Iwata said that the broadcast will be focused on games to be released through March 2012.