Tim Carman, from the Washington Post, has all of the details about food trucks serving during the inauguration.  Some highlights from the list are:

• Capital Chicken & Waffles will be making their debut during the inauguration.  Their truck build-out was just completed days ago!
• One truck from NYC made the list, named Make My Cake.  They will be serving in the National’s Ballpark area.
• Bada Bing won the lottery, but was denied a spot, likely due to its truck length and features.  Bada Bing is licensed in Arlington, but DC has different truck requirements which prevent the Bing from serving in DC (Inauguration trucks have to pass DC inspections).  Unfortunate. 🙁
• Crepes Parfait just let me know that they will also be serving! (UPDATE)

As for where to find your favorite DC food truck serving, I am just going to rely on real-time reports on the day of.  Trying to figure out the vending locations from the preliminary DCRA map (pdf) is pretty difficult and it seems to be missing the NW part of Penn Ave.

The full list of confirmed trucks, as per the Washington Post article mentioned above are: Goodies Frozen Custard, Borinquen Lunch Box, Big Cheese, Doug the Food Dude, Fojol Bros, Curbside Cupcakes, Cirque Cuisine, Carnivore BBQ, Capital Chicken & Waffles, Surfside, Sweetbites, Make My Cake, Pepe, and Crepes Parfait.