Haven't heard too much lately, but the Rumor Mill was churning a while ago about a CBR250RR 2-cyl that might make it to the states as a 300 or 350. It was shown with upgraded components like USD forks and an aluminum swingarm.
It would be fun if the major manufactures all wanted to own the 300 class, and were prepared to step it up. Not sure that's going to happen, but it would be neat.
CBR250RR article and video -
http://www.motorcycledaily.com/2016/...n-early-tests/