Interesting article on www.space.com today.
The paths of most stars in our galaxy have for many years been assumed to be circular orbits around the center of the galaxy. It's not quite so simple, though. Recently some scientists found that there are "streams" of suns that are moving in toward the center, and others moving out away from the center, and one of them is actually headed our way!
It's not quite time to duck, though - it'll be 1.4 million years before it gets to its closest proximity to our sun - and it will still be about a light year away. It will pass through the "Oort Cloud" of icy, rocky debris that orbits our sun at that distance, and it will probably stir it up quite a bit. A few thousand years after that, we may see a lot more comets and asteroids heading our way.
There is a very cool 3D movie that shows the motion of our neighboring stars - you can see it here. It takes a long time to download, even on a broadband connection, so be patient. It's worth it: Star Motion Movie.
For background data, see this page.
And if you ever wondered why the similarity between the spiral shape of a galaxy and the shape of a hurricane, they do a fair job of explaining it here.