Yeah, I'll be right here waiting on that one as well. I believe that if we do not succeed in exterminating ourselves first, that someday the Earth will either implode or explode, or the Sun will die and take the Earth with it or a comet or asteroid will finally be on target and take it out.
I would hope (I doubt it, but I can still hope) that before any of the scenarios described above take place that mankind will set aside all of these petty differences and perfect space exploration and travel and find other worlds to populate so that we can abandon Earth when (if) the time to do so comes.
Of course, now we have to discuss our sorry history of moving in somewhere where someone else already lives. Our track record in this regard is not all that great. :-)