...but something tells me he's a liar.
I also think he doesn't want to take the focus off his current projects.
I remember seeing am interview with Lucas in his private study. Behind him setting the scene was a bookshelf filled many of the books you would expect George Lucas to have. (Cambell, etc..)
Upon seeing the books in GL's library, a friend and I thought it would be interesting to still frame and zoom in on the book titles, just to see what George was reading.
Among the volumes was a recently published book called what else?
Telling Lies.
I think THIS may be the book in question.
So you never know what the future holds.
I also remember reading a post over at Episode-X that was an excellent collection of "Lucas Quotes" regarding the matter. He's actually said quite about the subject. (I wish I had saved that post.) He's actually said enough to make me think he's lying.
If I could read his mind right now, I would say that his hubris is telling him that the Star Wars TV show will last 7 to 10 years. Then after that series has run it's course, and possibly after another couple of years worth of media silence, he will suddenly decide to fullfill his original promise of 9 films.
A trilogy of trilogies.
Who knows...