I'd say it was due to multiple reasons, one of the bigger ones being the console and games weren't ready yet. 2nd, they wouldn't want the NS overshadowing Zelda U. If they showed off the console and the list of games, along with Zelda, chances are it could lose some of that fire it got during E3, and Ninten wouldn't want that to happen. And 3, perhaps it just works better with the current plan they're going with. With how quick word travels, there's no need to reveal a console several months in advance. It can be done much closer to the launch date, and spreading the info out keeps the console in people's minds, so they're less likely to move on and forget it.
Dance my pretties!
The Official Art Thread - The Official Manga Thread - The Official Starbound Thread
