"The ability to destroy a planet is insignificant next to the power of the Force."

[Yora]

In the early Star Wars movies, the Force was this amazing any mysterious thing. There's the amazing line from Vader and then later there is Yoda with "Wars do not make one great."

It's made very clear that the Force is not about combat powers. Both Vader and Yoda clearly believe that all this stuff with lightsabers and telekinesis are only trivial side details to the true significance of the Force. Sadly, since then it has become all about being able to hack through hordes of enemies with a lightsaber.

In a way, I think this is a pretty clear case of the writers hinting at something amazing and keeping it deliberately vague to maintain the mystery and understanding that it would be impossible to come up with a specific explanation that would be able to provide a satisfying payoff for that promise. The monster is always more scary when it's mostly hidden in the shadows. It's the few small bits that are visible that are enough to start the imagination and lead to a personal expectations of something amazing even when you have no specific idea what you expect would be there if you can see it. Same thing with mysteries.

But I think the implication here is that the full power of the Force lies in the abilities of precognition and telepathy. Even if it is impossible to come up with anything amazing enough to fully satisfy the expectations of that incredible mystic power, how could these initial hints be at least somewhat expanded? In what ways could these powers of seeeing different places and possible futures, and being able to sense and maipulate minds take on much more dramatic roles in a story. Even if it would be hard to come up with anything that makes the destruction of a planet look insignificant.

 

[Orc Knight]

Seems like it basically could boil down to controlling Fate and the outcomes to manipulate it how they want it. Which on a large scale might be able to change the course of entire planets and societies. Take the mind control effects and the like (even if it only works on the weak minded) and the control of the galaxy through subtly may be greater then exploding Alderaan. Not to the people there, but that may be something.

 

[CupofJoe]

Two things come to mind... In the current [movie based] Star Wars universe there isn't really anyone that has full control or knowledge of the Light side. Yoda was the last of the true Jedi. Luke did his best but we don't know what other training he got and he lost his most talented pupil.
So maybe all of the force that can be reached is the more physical and less philosophical areas.
And then there is George Lucas going on about the Whills.

 

[Yora]

Interestingly, in Episode 1 to 6 there's never been a Light Side. It's always just been The Force and the Dark Side of the Force.

I've always been thinking mostly about the ability to influence minds, but didn't see it as something as more impressive then blowing up whole planets. But now that it's mentioned, seeing the future could indeed be huge. Knowledge is power and the ability to transcend space and time and get impressions of possible future would be a real game changer. And since "always in motion the future is", it's not simply an I-Win-Button. It requires a lot of wisdom to understand what the Force shows and have a sense of what the consequences of different actions would be. To effectively make use of the foresight would require deep understanding of how the universe works, which in this case very significantly includes the Force.