We don't understand why expansion is occuring, so we can't say for certain. It would be a very long time in the future if that were to come to pass, and that's a whole lot of time for poorly-understood physics to happen in.

But yes, it is accellerating, and if it continues to do so, eventually it will overcome gravity. But like I said, this depends on an incomplete understanding of physics, and the current evidence suggests (inconclusively) that this outcome is unlikely. Check out dark energy if you want to learn more.