I think Van Ness is dead, because of the types of business that were there...furniture shops, offices, electronic stores, and the school crowd never brought much business in, probably because it's such a commuter school.
Demographically, it's the same. If you look at the houses off of Connecticut Ave from Cleveland...heck from Woodley to Chevy Chase, it's all the same. There is absolutely no change in demographics. It's just the type of businesses that grew in Cleveland Park (restaurants) vs. those in Van Ness (furniture, electronics, etc.)
I love Yosaku's sushi. It is good!
The only Thai I eat in NW is Fourty-Nine Twelve on Wisconsin Ave (4912)
IMO, that's the best Thai in NW. Much better than Jandara.
Angelica's is definately Georgetown, if I have the right place...next the Chinese restaurant?
I like Kavanaughs Pizza Pub on Wisconsin (Faccia Luna), and a little place called Cappuccino's also on Wisconsin Ave in G'Town.
Tenleytown has a couple other interesting places too, like the Dancing Crab (although Bethesda crab shack is better) and Guapo's. Which isn't great food at all, but their Margarita's and happy hour is a deal and a half.
If you've never been to the Calvert Woodley for wine, cheese and meats, you should really give it a try. Between C-W and Pearson's, you can find a host of wine steals.