The end of the article laments Einstein's retreat to 'simple mathematics' instead of following Bohr and company toward the complexity of Quantum Mechanics -- but this recent wired article suggests that perhaps Einstein was right all along: http://www.wired.com/2014/06/the-new-quantum-reality/
The last major hurdle for 1.0 (as I understand it) is final integration work with Atmosphere and updates to the package management system. While this is no small feat, it is far less of an engineering hurdle than either Blaze or the opLog tailing which was implemented in 0.7.0.
They are trying to solve the same problem: gatekeepers to any mutable data that affects your DOM -- but they do it in pretty different ways: (1) under the hood, Blaze tracks the DOM changes and applies them directly whereas React diffs the resultant HTML and applies the difference. (2) Blaze uses declarative templates for injecting HTML; React requires HTML to be built using virtual DOM elements in javascript.