ofcourse bitcoin will be there after 100 years, but not as popular as it is now. I don't people would be talking about bitcoin by then as there would be more number of crypto currencies and bitcoin would be one of them. Maybe it could carry the fame that it was the first and foremost one in its kind. i am sure that eastern and southern countries, the growth potential that they show now, would develop something that is more easier and affordable for them, the same will happen across the globe and it takes no time for each country to develop a cryto currency for its own.