Persistent Info* points to the Google Video blog and says it validates (as opposed to much of what Google's doing)... but hey, this is HTML 4.0 Transitional – including font tags and what-not. And I don't even mind the fact it doesn't validate anymore (1 error at this time). It just shows Google is still having new, or relatively new services without proper HTML (HTML4 Strict along with CSS, or XHTML1 Strict). Some services, of course, already show off much more modern HTML; Gmail, Maps, and so on. In fact, those that do often take DHTML to new levels.

* http://persistent.info/archives/2005/06/10/google-valid-html