@petehunt Certainly, and I don't disagree stylistically, but I did copy the style from https://github.com/facebook/react/blob/master/src/event/synthetic/SyntheticWheelEvent.js and https://github.com/facebook/react/blob/master/src/event/synthetic/SyntheticMouseEvent.js

Still want me to change?

Also, I've been thinking a bit more on ```key``` I should be able to get the most reasonable subset of it working at a small cost, cross-browser, although I'm not 100% sure yet.