For nintendo I'm not expecting anything special other than a few titles that have been anticipated for years now (zelda wii, golden sun DS, etc). Regarding 3DS I find it difficult to get hyped.
Sony: most of the show about the move, maybe a new cheaper PS3 SKU (that'd be nice), perhaps PSP2 announcement. But knowing sony it'll probably be overpriced with a lot of gimmick features and a weak library because sony never learns from their mistakes.
care to elaborate little bit more in-depth?
STOP SKITTLES!!
Urf.