Are you really concluding this using a static view gif vs an action one with tons of explosions and particle effects? I'd say it looks the same, the teaser doesn't show much. Maybe they'll show a proper trailer at VGA and then we'll see.

Different lighting/time of day too. And the E3 teaser was clearly a mini-cutscene.

Yes. Also I'm concluding the blue tunic is his main outfit.

Maybe it's his cloth at the beggining, like in Wind Waker and later he'll change into the green tunic. It would cool if they let us change whenever we wanted. 

The thing is that they have showed 3 times, and all of them that's his outfit. They always announce Zelda games with Link wearing his classic green tunic.

Reveal Trailers are usually nicer than the actual game, but it still looks quite nice..

hard to say though since there were only a few seconds of Zelda U shown :p

I know, maybe they wanted to do something diffrent. They also showed us some parts that look early into the game... we haven't seen much yet, not a single character, dialogue, story, lore, or even an exotic part of the world (like death mountain). So everything they showed us give me an "early vibe" to me. Either way, if that's the new tunic/outfit, I'd be fine with that. It looks great.

Me too. I hope they keep it because it looks badass.

that sword....is gigantic!!!! wowowowowwowwwwwwwwwwwwwwwwwwww

Looks to be just different lighting due to the time of day in game and a different area tbh.