I doubt my post will get seen in the rush of E3 posts here but I will try anyway:
Was this press conference a bit underwhelming? Yes.
Did I expect more from Nintendo, like core franchise title announcements, release dates etc.? Yes!
And did Nintendo also blew the chance hard to sell us all on the Wii U? Also yes... at first glance, I thought.
If I noticed something from Nintendo releasing the Wii against the HD twins, there actually seems a bit of tactical thinking in what they do. Microsoft has a huge financial backing so they could take the HD jump quite easily (on the expense of hardware reliability), Sony took quite a damage with the PS3 but managed to survive. What did Nintendo do? Overclock the Gamecube and R&D motion controls. It was very risky but it worked out, they made tons of money with little investment.
Now where are the tactics in such a mediocre E3 show? I will explain that, but their tactics might or might not have failed this time. I assume that none of the big games like Zelda, a 3D Mario, Smash Brothers, possibly F-Zero etc. would have been quite ready for launch. I assume that they might hold them back to have something to fire at Sony and Microsoft when they reveal the PS4 and the next XBOX. Much in the line of:
"Hey look here are the the other two next-gen consoles and we are totally more powerful than the Wii U!"
Nintendo: "Well you might be more powerful again but we have a 3D Mario in HD, a new F-Zero, a all new Zelda and Smash Brothers with fleshed out online functions, new IPs etc etc.! And this time we also appeal to multiplatform games, look at the Wii U Pro controller!"
Does this make more sense then to announce them right off the bat to try make everyone buy a Wii U first? Possibly, I'm not entirely sure about that one. If they would have launched all the megatons now without much to actually show anything concrete beyond early alpha versions people might still be unsure on buying a Wii U on launch. Afterall most people are not that informed and critical as we are on boards like here, they probably see the mainstream stuff that we exactly saw on the E3 conference and think "Alright." much like what the others did besides Ubisoft who tried a bit more.
It looks to me that Nintendo is saving the megatons to fight the PS4 and next XBOX more or less head-on when the games are more finished. Will this work out? Is this actually Nintendos plan? I don't know but sometimes they know what they are doing business wise, see Wii and sometimes they don't, see 3DS launch price. Lets just hope they know they are doing this time, afterall they also manged to pull a 180° shift with the 3DS.