It’s nice to know. I’ve worked on high-profile .NET project where I insisted as mad to be XHTML compliant, so I won’t have to code using tables since the content was screaming for simple layout.
I was able to persuade everyone in the end, but the damn thing got me lots of problems. All Web controls in ASP.NET 1.1 Framework produce the code which belongs to 1998. Pages for that projects are now mostly a bunch of divs and spans, since that was the closest I could get (without forsing the server-side guy to write complete set of custom controls for outputing meaningful markup).
It will still need work to make it all semantically meaningful, but changing divs and spans to hx & co. will be much simpler than turning table & co. to it.
Wait and see.