I can rattle of lots of restaurants in the Denver area that has closed recently. But I'm not really sure it's the economy. Seems like that's just a big part of that industy, especially the chef owned restaurant industry. The restaurant is or becomes the chef. They seems to work 7 days a week 52 weeks per year and just burn out! A terrible business model! The restaurant then closes and in comes another to start all over.
I can see no difference in trying to get a dinner reservation today, in one of the top rated good restaurants in town, than 2 to 3 years ago when the economy was supposingly better. It's still a tough chore. May people be buying less expensive wines or menu items, most certainly, but they are still going out to eat. If I notice a drop off in crowds, it's at restaurants that people didn't really want to go to anyway( mediocre food, wine,service, etc.), but went to because they couldn't get into their 1st or 2nd pick. More of those people are probably staying eating at home.