With the infrastructure slowly being built around it, I doubt BTC will be replaced. Especially if said businesses supporting it's usage grow exponentially after BTC garners more popularity. The only way I could see another crypto overtaking it would be through pure speculative value. However, I could see a similar idea like bitcoin being utilized and controlled by an already existing corporate entity that could successfully transition it to the mainstream. Also, have to factor in whether large corporations adopt bitcoin or whether they would go with this other idea. Right now bitcoin feels like an experiment, and many things can change from beta to alpha. Or whatever arbitrary stage you believe it's at so nobody can answer that question due to all the chaotic variables at play here.