According to stories on Gamasutra and Gamedaily, Nintendo's results will come Thursday (most likely very late Wendsday night/early Thursday morning given the time differences between the USA & Japan)
Sony's results are expected to come at approximately the same time, although I can't seem to find confirmation anywhere.
I'm expecting lifetime shipments for PS3 of 9.75 million and lifetime shipments of 20.5 million for Wii through 12/31/07. For reference, Microsoft announced 17.7 million consoles sold lifetime through 12/31/07.
Edit:
Through 3/31/2008 shipments to retail stand as:
Wii - 24.45 million
Xbox 360 - 19.0 million
PS3 - 12.81 million
People are difficult to govern because they have too much knowledge.
When there are more laws, there are more criminals.
- Lao Tzu