I'm ecouraged by the videos of people actually using the controllers, the Kotaku guys seemed to think the control fit the hands brilliantly, was easy to reach all the buttons/triggers and weight wise it was really light, lighter than an iPad was mentioned.
THAT is what it needs to be, sure it looks big and heavy but that doesn't necessarily mean it has to be
Nintendo wouldn't be so stupid as to put something out there that you couldn't physically use or sustain in the real world, it just wouldn't fly.
Certainly this is just the first unveiling, there will of course be information to come out at e3 as well as in the year to come in lead up to release, there are far too many assumptions coming through in the comments so far without any concrete evidence to support for or against the system.
Going to have to play the waiting game, however that being said, I am encouraged by Nintendo continuing to try to innovate while getting the 3rd parties back on side.