I'm really excited about the new Star Wars movies but would lose any and all enthusiasm if that rumor (which i think is BS) turns out to be true, that they're going to resurrect Darth Vader.
That's so stupid, it totally invalidates (in a dramatic character sense) the ending of ROTJ. And it would display such a massive lack of imagination, that it would just be a disappointment. "You were excited about seeing something new from Star Wars? HAHA sucks to be you, we're just doing a rehash".
I know Darth Vader is iconic, but the idea that the series can't survive as movies without him is actually pretty silly. People accept that Darth Vader is dead. He had about as definitive a death as possible. Nobody's really expecting to see him in Episode 7. Not necessary at all.