Although statements by their spokesmen are at times confusing Unizin's goals seem, at least to me, very clear.
What is Unizin? "A cloud-scale services operator for content, platforms and analytics steered by its members."
Unizin has already standardized on Canvas at the platform layer. The content and learning analytics layer are next. According to their timelines a "rudimentary repository" will be ready in Spring 2015 and a "rudimentary analytics platform" will be available in Summer 2015. Of course, the three major components will inter-operate using open standards. Unizin's endgame, therefore, doesn't seem to be a mystery.
What's not clear is when the "cloud-scale services" will come online, how the three component layers will be architected (e.g. what does "loosely coupled" mean exactly?), and when member institutions will start using it in production.