It is very possible that ethereum will be the next big thing in the crypto currency market the way things are going at the moment but not that it will overtake Bitcoin but will remain only best alternative to Bitcoin.
I do not know why you called ethereum the next big thing, ethereum has already made it, it is the second coin in the market cap and the only coin above it is the coin that created this market in the first place so ethereum cannot climb any more positions, if you are looking for the next big thing then invest in icos.