Better ETA calculations.
For some reason the ETA predictions by WAZE are way off. One example was at the start of my trip it predicted I would arrive around 10:30pm (this was at 8:30am). This figure remained constant until I was 2/3rds of the way there, when it got a little more accurate, but still 4 hours off. I actually arrived at 2:30pm.
It seems that Waze calculates the ETA based on the current road traffic. However when you drive a long path the traffic changes as you go. Waze could have collected statistics on the traffic (especially during rush hours like morning, evening, holidays) and use those statistics to improve the ETA calculation. For example if I leave home at 08:00 o'clock and roads are clear but the statistics show that on 08:30 traffic is build right on my route Waze should consider that in its calculations.