I've been playing around with canvas & excanvas to try and get some text effects working nicely in IE (as its shadow filters are rendered horribly) and it all works except that it's not applying the @font-face family (testing with a google web font).
I'm ensuring that the font is loaded and rendering (by doing measurements) before trying to render the canvas but IE is still using the fallback font rather than the @font-face defined one. I've even tried adding a massive delay of 4 seconds after the font is loaded before attempting to render the canvas in IE.
Not a fun answer - but @font-face fonts are often included as a src:url() stack that includes an svg version of the font. You might be able to convert the svg version of the font to vml and use it directly.