Fear of idea theft kept Mario 128 out of E3 2003
Nintendo's intention was to reveal the next game in the legendary Mario franchise, Mario 128, at last month's E3 but chose not to at the final minute in fear of other developers stealing ideas from the game, which will apparently be radically different and god-like (for a Mario game and for video games in general).
Speculation abounds as to when the game will be released. It's entirely possible that it can come out this year (since the game was far enough in development to be shown at E3) but a 2004 date is almost definite.
Source: gamesindustry.biz