It's an interesting question. I see Ripple as more of a competitor of cryptocurrencies in that it isn't truly a cryptocurrency, but is offered in the same market. It's really an alternative to cryptocurrencies. In that sense, I don't know if it lends any legitimacy to the other currencies, particularly because its selling point is that it is supposedly safer and more secure being that it is backed by establishment institutions. If anything, it may be taking away from the market and diverting money that would otherwise support it back to the banks and establishment institutions.
I get my news from all over the place. I follow most currencies in which I'm interested on Twitter. I often pore over market movements and when I see something changing, I quickly look for news about that particular movement. So yeah, I don't really have a single good source.