This is fantastic, and I am almost upset by how little info the keynote address included. Obviously there will be a ton of detail coming out this week with the labs and documentation being released, looking forward to that.

As an iOS developer, this is by far the biggest announcement. This has huge potential to provide value to me and my team. I'm looking forward to ripping out programmatic NSLayoutConstraint and Interface Builder from my projects ASAP. This seems like it includes much more than that, however.