Yes, because it is such an unproven area there is a lot of room for changes. For example something Litecoin is working on is verifying Litecoin nodes with as little as 200-300MB of disk storage. Now that's just an example, but I could see stuff like that making a currency in the future based on BTC more popular than BTC itself is all. The arena is too new I think for me or anyone else to say BTC is going to be it.