Zach Leatherman posed the question of the community on Twitter: web fonts or webfonts?
Which resulted in the observation that CSS Fonts 4 currently uses both forms. (CSS Fonts 3, in contrast, was firmly in the whitespace-separator camp.)
Now, I voted for two words, for clarity, but as with all things web standards, my main concern is consistency. Pick one & stick with it.
Those of you who are in Paris, please consider this a conversation starter for discussion over fine food & wine. Happy bikeshedding.