Expectations are high ahead of today’s WWDC keynote, with big improvements to Siri assumed to be a focal point of the event. Apple is expected to release a third-party Siri SDK for developers and is rumored to be putting out some kind of Siri-capable hardware device to rival Amazon’s Echo, though the latter isn’t expected to make an appearance today. “Sweeping changes” to Apple Music are also anticipated as part of the…