I think the most visible difference will remain that React is code centric, with templates as a sort of special case of code. Angular (1, 2) is more explicitly divided between code and template.
I believe the main driver in choosing between them will not be technical, but cultural. There are many organizations where considerable value is ascribed to the notion of code versus template, such organizations might lean toward Angular (especially in version 2) over React and friends.
Aurelia seems to be the best ideas from Angular + the best ideas from the creator's previous framework, Durandal, in one framework with much cleaner syntax and much less complexity than both Angular & Angular 2.0.
Ember has made some big updates recently, rewriting their rendering engine to use a virtual DOM.
A lot of people still seem to really like Meteor.
Mercury, Mithril, Ractive, JSBlocks, etc. are all smaller, lesser known projects with a lot of potential.
Meteor officially supports React and Angular. Meteor is a web and mobile development platform, not a front-end framework.
It supports React and Angular as of recently, I suspect, simply to maintain itself as a competitor to other stacks, due to the extreme popularity of React and Angular.
Learning all of the libraries and frameworks for React is quite complex and not less complex then learning Angular 2.0. with its backwards compatible support.
When you say it's not a "framework" I don't even understand what you mean by "framework". If you mean a system that locks you into one way of doing things and is hard to integrate with other tools, then by all means, it's not a framework, and then I don't want it anyway.
I never said that , don't put words in my mouth. The rest of your comment is irrelevant since you're making stuff up.
Yes, the future will be web components, which would mean Polymer / x-tag until the spec is in all modern browsers. React will die when web components don't need polyfills.
For anything larger than a simple widget, I highly doubt you will see a move to use native web components for a long time. There are application architecture issues they have not even begun to tackle.