Not only this is optmistic in EoE, it made me happy.
I'm reminded of that scene from Naked Gun where they're leaving a showing of Platoon laughing with happiness.
I think calling EoTV or EoE optimistic is a stretch.
Eotv's optimistic message is pretty much just two lines at the end, lines which state the obvious. Eotv never really struck me as being about important messages anyway. The ending to me seemed more like one of those bleak, twilight zone twist endings.
EoE's message was "YOU ARE A DIGUSTING WRETCH! THE LOWEST OF THE LOW!"
With a dash of "it's upto you to change that."
Evangelion really isn't about optimistic messages to live by. Evangelion is more like the bully who made you stand up for yourself by beating you up, or someone who motivated you into making something of yourself by calling you a pathetic loser.
What I find difficult to fathom is what, if anything, Shinji can actually do in the next film. He's not getting into an Eva ever again, that's for sure. Perhaps hope, for Shinji, will involve the realisation that the world doesn't revolve around him and that he should simply let Wille do what they have to do without him.
That would piss me off if anno does that. Shinji leaving eva with a whimper and with the destruction of the world being the greatest thing he did. It wouldn't suprise me if he did that though. It has the same frustrating and ball busting feel as all the other stuff he's done with Shinji in evangelion. Being a negative caricature of sucking really does seem to be Shinji's unfortunate and unchanging purpose in evangelion.
The preview wasn't wrong; it was just for an episode that we skipped. :P I'm convinced that it was a really clever plot device to allude to the events that occurred during the time skip while keeping the events of Q a complete surprise.
Slaps in the face work best when they have the element of surprise.