At the highest levels, most racers still use tubulars. On cyclingnews.com, they recently had a small feature about pros using "what they wanted" instead of what their sponsors made, and it included a pic of tubulars with Michelin logos, although Michelin does not currently offer any tubular tires.
The big modern day advantage of tubulars is that they allow the use of full carbon fiber rims, rather than carbon/metal hybrids that are usually necessary for clinchers. This can shave a half pound or so off a wheelset.
I think a moderate number of amateur racers are still using sewups, but it isn't like it was 20+ years ago when pretty much everybody was doing so.
This applies to the U.S. Given that I still see tubulars in the bicycle section of the equivalent of WalMart in France, I'd think that more people are using them there.