I've been toying with the idea of getting one of those silicon keyboard covers, it popped up as a suggested purchase on Amazon the other day when I was looking for something else... Seems rather sensible, I've already had a stuck full stop key on my new machine...
The new keyboard mechanisms are covered in silicone to stop dust from getting in.
https://ifixit.org/blog/10279/apple-macbook-keyboard-cover-up/