What do you call Asteroid that people Thought was Meteorite?
Meteowrong
(Ba Dum Tish)

Although interestingly enough, as I far as I remember, the kinds of distances involved with a collision event like this means that when it comes down to it, nothing really bad will happen to our solar system. The night sky (ignoring for a moment all that stuff about the expanding sun) would just look a million times more cool.

Galaxy-wide, the greater orbits of the stars around the core will be completely wrecked. If humanity were spread out across a substantial chunk of stars (perhaps one of the "swirls" of our galaxy), those stars would all get flung away from each other over the course of hundreds of millions of years.

Potentially, an event like this would fling the seeds of humanity far and wide, eventually leaving them too far away from each other to continue sustained contact.

… this sounds like a cool idea for a sci-fi book.