Hi Byron! I love the relaxing atmosphere of the San Angel Inn in Epcot's Mexico Pavilion!
At this time, the list of restaurants participating in the 2012 Disney Dining Plan is incomplete, and we likely won't see the final list until January. Not all of the restaurants in Epcot are owned by Disney, and therefore, they must elect each year whether to participate in the Disney Dining Plan. Those decisions generally aren't made until the end of the year. We usually see a bunch of eateries added to the list of participating restaurants at the end of December or beginning of January. I recommend that for purposes of making your dining reservations, you assume that restaurants currently participating in the Dining Plan will continue to do so, but check the list again toward the end of the year to make sure so you can make any last-minute changes before your trip. I hope you'll find San Angel Inn on the list then!