tingly thought approach:
overall cryptocurrencies seem like a squid grabbing and absorbing fiat from all sides.
as soon as volatile altcoins crash or drive into bearphase its holders would either cash out in fiat or - more logically (once a coiner always a coiner  ) change to bitcoin due to its grown stability and it could get the role similar to a gold standard.

i'm really waiting for the time until big companies start their own altcoins (which probably function more like ripple).
the potential consuming power will gradually become highly visible for many markets. (gaming industry, ecommerce etc.)
i suppose you can soon even interchange Bitcoin for AmazonCoin.