Bitcoin in the future will have changed drastically I think, not in the sense of its value but how we look at bitcoin itself. We will have determined if it is truly a new form of currency or a solid investment option, it will be through this decision that we can truly place a value on Bitcoin I think honestly. If we see it as a currency then yes I believe it will be replaced by one of the alt coins because they are  easier to use for payments then Bitcoin has been at least in my own personal experimce. However if we see it as an investment then you have those that are loyal to Bitcoin and will hold their coins to drive demand up and help their investments become more valuable.