Google Maps for desktop and mobile has added live transit updates, which can tell you when your ride is actually going to arrive. Google has partnered with transit agencies to integrate live transit data in four US cities and two European cities: Boston, Portland (Oregon), San Diego, San Francisco, Madrid, and Turin.
This feature has been rolled out for Google Maps on all supported desktop and mobile browsers as well as the latest version of Google Maps for mobile (requires Android 1.6+). The search giant currently only supports Android and iOS for mobile browsers and has not detailed plans to add more support.
The new addition includes live departure times (indicated with a special icon) as well as service alerts. You can click on a transit station to find out more information, or plan a transit route that will show you delays or alerts related to your trip.
The rollout is very small, which is typical for Google's strategy for rolling out brand new features. The company of course says it is still working with its public transit partners to provide live data to more people in more cities, but isn't offering a timeframe or further details.
I live in Toronto, where public transit is atrocious. While the Toronto Transit Commission (TTC) has various plans to improve its service, including options to see when the next bus will arrive, it still has long way to go. I sincerely hope that Google will be able to hurry up the process and I'll be able to find TTC live updates on my phone, but something tells me that's just wishful thinking.