When Apple created its own Maps application for iOS 6 and dropped Google Maps as the default mapping app, transit data was one of many casualties (the rumors are that Google asked for more information about maps users to better target ads, and Apple refused for privacy reasons). Since then, it's been expected that they would bring transit directions back to their Maps app, especially because they've bought many small companies that specialize in mapping and transit, but so far, zero, zip, zilch, nada... Not even a word about it at last week's big developer event where the next version of the OS for iPhones and iPads was unveiled.
Not a word, but apparently a picture that we weren't supposed to see slipped through.
A sharp-eyed individual noticed the icon above on one of the slides from a WWDC developer session. There's pretty good circumstantial evidence that this was supposed to be a secret, because Apple has already removed the presentation and video from the session from its website.
Hopefully this means that transit directions will be back to Apple Maps soon (hopefully in a 8.1 update, rather than in next year's iOS 9). Nothing keeps people from downloading a third party mapping app (such as Google Maps) and getting transit directions there, but we know the power of defaults; most people won't bother installing another maps app, and if that makes transit directions less available, it could discourage some people from using this green way to get around.