Google's excanvas only works in quirks mode for IE8. IE8 in act-as-IE8 mode disables VML but doesn’t implement canvas, so there’s currently no 2D drawing method for that browser. UPDATE: The problem is Google’s excanvas library, not IE8 disabling VML; see comments.
According to an update on that article, .
I was getting worried about not being able to re-route driving directions in Google Maps using VML, but then I remembered I'll never actually use IE8.