It's kinda sad for Win7 Phone. Right now, all the browser innovation is beginning to have its base on mobile devices. I think it's thanks to the webkit implementation on the iPhone that traction for HTML5 has accelerated on the last two years.

All modern smartphones have some kind of HTML 5 support and most mobile websites use the iPhone as their main target. So it is sad to see so many good decisions on Win7 Phone going to waste because of really old/legacy technology.

I guess it's impossible for Microsoft to use Webkit, politically speaking.