Well, the speakers are mostly listed, Greg Heo's pre-conf Swift tutorial is arranged, and the bookings are going well (a third of all tickets gone with six weeks left until the end of early booking). Now we need to sort out the Hack for Thursday.
My first thought was a SpriteKit hack - we haven't done a Games hack since 2012, when Chris Wilson got us going with Cocos2D. SpriteKit is so much easier, and useful for other things too (nice talk about that in the conference...). We could run a tutorial on it alongside Greg's tutorial on Monday, and then get in nearly 12 hours of hacking on the Thursday.
Another possibility might be getting Siri into your App - I'm convinced Apple are going to announce proper Siri integration with third party apps at WWDC, hence the Hey Siri intro to this year's WWDC.
We certainly won't make any decision until after WWDC but we'd be interested in your thoughts about what would be a good hack. Please add your comments!
(Other past hacks - talking to Arduino devices, iBeacons, Watch apps)