I believe Ripple and Stellar can coexist. Personally I'm diversified about 60/40 XRP/XLM. Very exciting gains from both have been coming and hopefully will continue.
That being said, I'm also under the impression that Ripple has a bit more of a foothold in the market that they're specifically trying to grasp currently. At this point, if Ripple doesn't make any mistakes, it really is to the moon.
Edit: Brainfart meant to respond to another thread about ripple, regardless my answer stands. I don't think their prices are as linked as they seem, but if it goes up, good for all of us!