I am a MEGA Green Day fan, and i want to know if Green Day has gone Emo, or did Punk change first. i personally think they are Still Punk, but what do you think?
I'd say Green Day is one in their own right now. Speaking from the point of a view of somebody who's been listening to them for 13 years, they have changed quite a bit. And as they have changed, new genres and sub-genres have formed. I think it's difficult to describe one band as one specific genre, with all the retarded names that are out there for the different ones.

Basically, asking for a genre classing is nearly pointless now. Especially with somebody as debated as Green Day.

Also, I hate the whole "OMG mah fave band went emoz ;_\\\" thing. It's so juvenile.
If only summer rain would fall, on the houses and the boulevards
And the sidewalk bagatelles, it's like a dream
With the roar of cars and the lulling of the cafe bars,
The sweetly sleeping sweeping of the Seine...
Green day doesn't even vaguely resemble any type of "emo," and punk has been changing constantly for the past 35 odd years.

Does that answer your question?