New Star Wars movie will it be a bust

So the continuation of the Star Wars saga continues with Chapter 7: The Force Awakens. Why they are doing another Star Wars movie?  It puzzles me because the last was supposed to be the end; Darth Vader and the Emperor, both die so who is there to be the villain-- unless they turn Luke Skywalker into a villain, which would be the same thing they did to Anakin, aka Darth Vader. Plus all of the heroes are gone, like Obi Wan, Yoda, and Anakin. However, if they were to turn Luke into a villain, who would be the one to defeat him, because all of the heroes have died throughout the series of Star Wars? Plus it would just get boring seeing Luke turn into a villain because it has already been done in the series. However there are some rumors that Count Dooku, who had supposedly been killed, will be reborn and become the villan. If so, there might be hope for this movie after all. So one thing is for sure: the new Star Wars movie will sure be interesting. I can't wait to see if it sinks or swims.