Ok.

Apparently it IS lame to think up problems when you're bored. So here's the answer. The balls will not reach the end at the same time. They will however have the same velocity when they exit the "bump" in the track.

The ball which goes downhill first and then uphill will finish first, since its speed will never drop below the speed it started out with. It will speed up down the hill, and then slow down to its original speed when it goes up the other side.

The other ball will slow down initially when it goes up the hill, and then will speed up again to its original speed when it goes down the other side. Unfortunantly, it will finish last. But of all the balls that finished last, it was the best.