Is it possible that Bitcoins are the store of wealth (gold) whereas Ripples or NXT will be the more commonly used everyday exchanged digital currency? Just a thought.
Possible, but not likely, since if Ripple takes off, XRP (ripples) will become viable as a store of value too. What does seem likely is that Bitcoin will evolve to support some sort of rippling mechanism. Both Ripple and Bitcoin will also likely adopt innovations from Zerocoin/Zerocash and future alt-coins if they are successful.