Just saw this thread yesterday and just finished reading through the entire thread (yes, I have nothing else to do with my life), and I thought I'd share some thoughts.
I live in DC, am in my early 30s, and have had many opportunities to wear black tie in this town. On average, I have worn black tie 5-6 times a year in the last three and a half years or so. I've mainly worn it to:
- opening nights of the opera at the Kennedy Center
- Viennese balls (there are at least five that I know of that take place in this town every year), not to mention other less formal but "black tie requested" types of balls (NYE etc.)
- my office Christmas party, which is black tie optional
And I'm not even counting the four inaugural balls that I attended - one of which was an official one - when Obama became president in January 2009. There are also a lot of black tie fundraiser galas in this town, but I rarely go to those, as I think they are stuffy and boring. To me, black tie is supposed to be worn when you're feeling festive and having fun, not when you have to sit down at a table for hours listening to speeches and making small talk with strangers whose company you might not appreciate.
I admit that some of the events I listed above are a bit "niche" in nature (there's not much point in going to a Viennese ball if you don't like waltz, and not all companies have black tie optional Christmas parties), but my feeling is that black tie is far from dead in DC and if you are determined enough, you can find your way to at least one or two black tie events every year. I also have the impression that people who do go to these events take black tie seriously. While compliance with the black tie "gold standard" may vary, at none of those events that I attended did I feel overdressed or out of place in my tux, as many others who attended would also be in black tie. At the Viennese balls, some people even turn up in full white tie rigs!
What I do miss however, are opportunities to wear black tie in more intimate settings, like a house party for instance. I obviously do not move in rarified enough circles to be invited to such parties (if they indeed do exist.)