“A 2006 survey by Pew Research found that 85 percent of teenagers online had a MySpace account. Today, only 7 percent of teens maintain an account there.” (nyt)
Evolution.. who knows? I bet yes, in 10 years Facebook will be there, but will change a lot, the fight to not become irrelevant happen at every new feature roll out… One day also Facebook will pivot and will be the most natural choice, un-noticed.