First, the bad news: Windows Phone 8 will not run on existing devices. Terry Myerson said it just like that on stage, and it's a big bummer for all of the exciting new features announced...or is it?

As a consolation to legacy devices, a new update is in the works called Windows Phone 7.8 which will bring over a subset of features found in the Apollo software. The only confirmed new feature that will make it over to legacy devices is the all-new Start page, but presumably there will be more.