Great questions -- For starters, one important thing to note is that Structure Core is like a "raw component" is designed to be embedded into other products like VR headsets or robots, and isn't designed for directly attaching to iOS devices like the Structure Sensor is. One of the distinctions is that Structure Core has a visible camera and IMU onboard, whereas Structure Sensor uses the iOS device for these functions.
We demonstrated Structure Core at CES early this year, but haven't made any new announcements on when it might be available for general purchase. For now, we're very interested to hear from folks who are interested to integrate Structure Core into their projects, and we set up a page for people interested to learn more: http://structure.io/core
PS -- In case you didn't catch it, as of Structure SDK 0.6 together with Firmware 2.0, your Structure Sensor gets a great accuracy boost when you use apps like Room Capture -- so it's getting better even without new optics.