I'm excited about this. I actually wouldn't mind if Waze was shut down instead of the 3-year period, as long as Google assimilated all of its technology.
It would be fantastic to have Google both data mining traffic data (as it does now) and also combining this with user-volunteered traffic reports. Each technology has something to offer the other, and it will be really cool to bring in the best of both worlds. I'm very confident about this acquisition, it feels like it wasn't just an acqui-hire.