I reported many months ago that Microsoft's Virtual Earth web app was using SVG to render path data when getting directions. At the time, I complained that Google Maps was not yet doing it, though their code looked like it supported it. I was looking for directions and decided to check it out using Firefox's DOM Inspector - and sure enough, they are using SVG now to draw the path data in Firefox 2 (and using Microsoft's VML in Internet Explorer).
Ironically, Virtual Earth looks like it has much more functionality, yet most of it is broken in Firefox 2 (not in Firefox 1.5). For instance, the paths are not showing up for me in Firefox 2. Furthermore, Virtual Earth seem completely broken in Opera 9 which is a significant step backwards from 5 months ago.