Haha, good call. Nah, that one took a coupla years to develop ... maybe with the speed of information the way it is now, the world might come to that conclusion in a lot less time, though. Give it a fortnight, maybe?
It would depend on who was right. Obviously there would be mass conversions to the correct religion. There would also be millions that would still be in denial. It reminds me of that southpark episode #58where everyone is being processed in hell after they died. The Hell Director says: I'm afraid it was the Mormons. Yes, the Mormons were the correct answer.
As a Christian, I'm quite confident that God will reveal himself--again--to the people of Earth just as he said he would. I think the "Left Behind" series of novels sets it up in an interesting way, although I didn't agree with everything in them. God will not return as Jesus and go through what he went through before---been there, done that, quite literally. Will there be people who still won't believe in him? Of course. What will happen to them? Well, ultimately they will be eternally separated from God, and whether you want to define that as being cast into the pit, burned in eternal fire, whatever, it will not be what you want to have happen to you, that's for sure.
I think when God does reveal Himself again, it'll be fairly obvious, since as Dave said, He's already come down amongst us as a normal man. I'm not sure that He'll come down in blinding light and all that, like the book of Revelation says, but I think we'll definitely know when it happens.
Well I have family who are Kuwait citizens/Muslim and we had a good talk this summer on religion, mostly theirs. They believe as Christians and Jews do in that we both pray to the same God. The main difference in in them is the "prophets" of God. Christians (Jesus), Islam (Mohammed), and the Jew's are still waiting for theirs. But I believe that most followers of the three would agree that we shall go to the father not him to us. But that is just my take on it.