When Lucas decides to turn the live action series into another trilogy everything will be just fine
This is probably pretty close to the truth.
Eventually, and it probably won't be until near the end of this decade, Lucas will decide that more live-action Star Wars (movies or maybe even TV) is needed to truly keep the "Star Wars is Forever" thing going.
As horrible as it is to say, I think we're definitely in for more stuff once Lucas passes too. It's not like Lucasfilm is going to be like "oh well, no more Star Wars". Even if they just start to mine the EU and focus on the stuff that on a high-level he approved.
We could end up with a situation like what happened with Star Trek: Deep Space Nine - Roddenberry had passed on, but before he died, he had been in discussions about the possibility of doing a Trek show set on a space station, so the same could happen with Star Wars - ideas Lucas had bounced around in various discussions/meetings/etc... could be fleshed out and turned into movies.
A trilogy of movies based on The Force Unleashed games or one based on the KOTOR games would be easy and there is enough story in both of the two games released that a third movie could easily be written for either storyline that brings everything from the two games together in a satisfying conclusion. And either trilogy could still bare the name "George Lucas" since he was involved in the approval process of both storylines.
And if games aren't a good enough source, then do what Marvel is doing, mine the comics. Heck - release a super-realistic 3D animated feature that brings Shadows of the Empire to the big screen - almost like Star Wars: Episode 5.5.
As long as Star Wars makes money - whether that be movie ticket sales, TV ad-revenue, merchandising, or books/comics - Star Wars will keep going for a long time to come.