(FT 3) Nikon, Canon and Olympus DSLR at the end of March?

Ken Rockwell speculates a new Nikon D40 for the trade show in Tokyo on March 26th.

http://www.photoimagingexpo.com/01_01.html

Probably the Canon 450d successor will come on March 25th.

Is that the right time for Olympus to show a new DSLR? What about Panasonic?