This is a copy from another thread; Epcot's hours are from 9-12 midnight on EMH nights, BUT:
Although the official closing time of Epcot will be midnight (3 hours past the 9 pm closing of WS), there will ONLY be certain attractions open during the EMHs:
El Rio del Tiempo
Honey, I Shrunk the Audience
Journey Into Imagination With Figment
Maelstrom
Mission: SPACE®
Spaceship Earth
Test Track
Universe of Energy
As far as the World Showcase, note that only 2 rides/pavilions are open: Mexico and Norway. Some previous posters have mentioned that the CM's will rope off the WS at Norway, not allowing anyone to even stroll through the World.
So, although you get an additional 3 hours, you have to make the decision if the above attractions are worth it...to each his own!
Hope this answers your question!