Apple adopting Bitcoin isn't even remotely likely. Simply put, it is impossible that Apple will adopt Bitcoin.
The term adoption when used in relation to Bitcoin is consistently misused. When merchants use a service that accepts Bitcoin from holders and converts it into fiat for themselves, they are not adopting Bitcoin. They are exploiting the popularity of the term and converting BTC into fiat. This is not a case of merchants helping Bitcoin but a case of Bitcoin helping merchants. Equally, overall fiat conversion into Bitcoin isn't increasing but decreasing.
Bitcoin is being stress tested and the question isn't which load will make it move faster but which push will make the load lighter. And I see no discussion regarding real Bitcoin development. NXT, Ethereum, Exocoin, NEM and maybe even to a certain degree Monero and Emunie are where development, not armchair discussions about development, is happening.
It is impossible to know which child will grow to be the greatest adult though even if we knew, we still would be left with a definition of great that may be incorrect.
Bitcoin has hit adulthood and is great but it is very limited. Trying to change the definition of 'great' only helps with making it impossible to call Bitcoin great without doing a single bit of work toward making it greater.
Actually I would say BitsharesX is probably better than any other competitor to bitcoin that you have listed there.. its got alot of things going for it and I think it would tag along with bitcoin for a while as bitcoin would be used as a currency and bitshares used for well, everything else including anything that shares are issued for (stocks, bonds, any assets(voting, music, dns)).. NXT tries to do the same thing but doesn't do it quite aswell.. and the other ones I dont think are even close (yet). I think the winner will be the ones that will complement bitcoin not replace it.
The winner is never defined as the one who complements number 1. To be the winner a cryptocurrency has to necessarily replace Bitcoin.
The most basic reason why Bitcoin cannot and will not persist long term is that it requires large processing power as well as storage capacity but offers a tiny number of transactions per second at 7. The exponential nature of technology doesn't concern me when it comes to the processing power and storage requirements. What concerns me is how little it delivers for so much consumption. Meanwhile NXT which is an early 2.0 is over there featuring 100tps right now and eyeing 1000tps. SPV nodes don't really offset this either.
Another reason that comes to mind is the fact that satoshi and at least whoever has gox stolen coins holds hundreds of thousands of BTC. So much for not trusting FIAT and going to BTC because it is 'decentralized' as the useful idiots keep repeating. FIAT is magnitudes more decentralized than Bitcoin as it is currently distributed.
I understand that Bitcoin could be changed to handle more but that increase will cause a proportional increase in processing power and storage requirements which means it will keep being really slow.