I wasn't particularly impressed by anything that any of the press conferences had on display; in particular, I didn't see any one annoucement that 'rocked' E3 ...
With that said, I think Sony delivered a conference which gave current PS3 owners (and people who intend to buy a PS3) a lot to be excited about ...
I could be wrong but, I expect Nintendo's annoucement of Wii Fit can not be under estimated; their annoucement of Brain Training was not well recieved in 2005 but it is/was one of the most important videogames released in recent years.