It depends on how that happens and how society is affected. It would never magically disappear without cause, and if it were never in existence it's hard to predict what society would have turned out like.
I think it'd be great if it dies out eventually, though. Or at the very least, gets rids of fundamentalism. Increased education may help with that. I don't think it's likely at all though....nor would I support "outlawing" of religion outright.
Christopher Hitchens tells a story about how he answered this question and how Richard Dawkins reacted.
[YOUTUBE="Eyk1QkaFVMs"]Last Theist[/YOUTUBE]
Sounds boring...and like it wouldn't make a difference with fighting. A lot of wars are not caused by religion, they just use it as an excuse, or other people seem to assume so.
I wonder what happens to the spiritual impulse in a world which is even more athiest than the status quo
Okay, who hacked gromit's account?
Whilst I don't know what that means, last I checked there's over a billion religious atheists, and even more non-religious but spiritual ones (whatever that means).
I think the spiritual stuff would keep going strong. The atheistic religions would spread a lot faster with reduced competition and people's desire for "spirituality" would still be around.
You checked? How did you check?
As an atheist I'd have to say: No.
Shitheadedness is not determined by one's belief in the existence of "god" (who/whom/whatever it maybe) I'm afraid.