Fair or not, Nintendo always has the greatest expectations on them going into their annual press conference, because they're the only company that doesn't (intentionally or unintentionally) leak their games to the press. So I do think there's a lot of truth in us being disappointed because Nintendo showed nothing new.
However, there were three things I wanted to see going into this press conference:
1. I wanted to see Nintendo make a strong case for why I would want to play games using the Wii U GamePad, so much that I would buy the Wii U versions of 3rd party games over just their PS3 or 360 verisons.
I owned a DS once upon a time, and (outside of maybe The World Ends With You) I never found the 2nd screen to be altogether useful. Hooray, I can look at lazily-implemented maps and sub-screens! I couldn't do that before just by pausing my game! Nintendo didn't sell me on that GamePad, and without that the Wii U is a hard sell for me.
2. After 6 years of casual-oriented shovelware on Wii, I wanted to see a sign from Nintendo that they were ready to actually live up to their promises last year and cater to us more, the people who stayed even when the casuals abandoned the Wii. Now, I don't mean that they should exclude the casuals. I'm happy there were games for them at that press conference. After all, the casuals were the life of the Wii for the first 2-3 years of the Wii, but they were also the downfall of the Wii for the rest of its lifespan when they left for mobile phones and Kinect.
I suppose after years of Nintendo being probably a 30/70 split core vs. casuals in their lineup, I was hoping (especially after their comments last year) that maybe that split might get evened up to something like 60/40 in our favor. The casuals are not going to buy this system, at least not to the degree that they bought the Wii (really, what could?). Most of that market has been lost to other devices, and a weak touchscreen controller isn't going to bring them back.
3. I really wanted Nintendo to show me something exciting at that press conference, something that would make me say "**** YES! I am buying that DAY ONE!" And Retro's game would probably have done that, since they are Nintendo's best studio IMO. As much as I liked the original Pikmin, I was very lukewarm on Pikmin 2 and Pikmin 3 seemed like more of the same. It looked cool, but not exciting. Something exciting would be a reveal like the one for Metroid Other M a few years back, which looked so new and different from Nintendo and really got me hopeful for 2D Metroid actually appealing to me for once. Instead, this year Nintendo revealed...Nintendoland, a mini-game collection. Because we didn't get enough of that **** on the Wii. Lame.
I really wanted to be excited for the Wii U after this press conference, especially after how mediocre E3 in general has been this year. But I just saw nothing worth getting excited about at that press conference, and I don't care if a game that would do that wouldn't be ready at launch. Nintendo needed to show awesome software regardless of how far off their release date was. System launches are all about potential, the future of the device. I didn't see a future for the Wii at the press conference, just an incredibly lame present. The Wii U just looked like more of the Wii years, but in HD, and I didn't like the Wii years.