Hard to say without defining "predominant" - many of the metrics being used such as "market cap" are highly flawed. Also, it's easy to envision a future where say, Facebook or Amazon creates a "cryptocurrency" that all of their users are incentivized to adopt, which could easily result in a cryptocurrency with far greater adoption than any currently in existence. But would that cryptocurrency have the same properties as Bitcoin? Highly unlikely...
With regard to clever new projects I'm keeping an eye on Grin.