Looking ahead: Native font events
Bram Stein, writing for Typekit:
The CSS3 Fonts Module recently introduced a new interface on the document object called fontloader. This interface can be used to explicitly load web fonts, or to notify when a font has loaded (or failed to load). […]
The fontloader interface is pretty straightforward, and it will appear familiar as it was partly influenced by the design of the open-source webfontloader library that Typekit collaborates on and uses in kits. It has three properties called onloadstart, onload and onerror for when a font starts loading, when it finishes loading, and when it has failed to load.