If it's such a technical difficulty, how does Opera manage to pass it still?
Sounds better than "It was too hard for us. Sorry."
I realize that there's a bit of a chicken-and-egg problem with browsers not supporting it, but it seems to me that the really good features start picking up traction even when only a few browsers support it (e.g. CSS transitions and animations, the latter of which Firefox still doesn't support).
We sure can implement a broken version of SVG Fonts just to pass Acid3. We think doing that is 1) unethical and 2) bad for the web. So we're not going to do that.