The reason io.js was forked, in my opinion, is because a core group of very strong contributors wanted control over Node. They gained that control by forking, giving away control of the fork to the community (open governance model) and working to make the fork a superior product.
Technically, io.js' v8 version in release 1.4.1 is unsupported as well; it was released 01/07, and Google's support of v8 ends when it is replaced by the next version (their release/support cycle is 6 weeks).
I'm not sure that this is correct. io.js 1.4.1 just shipped with v8 version 4.1.0.21[0] which was released on 2/24/15[1]. Additionally, the post which you quoted specifically says that "4.1 -> Chrome 41" and "and every branch's support period is also the same (another ~6 weeks until the next Chrome version goes on the stable channel)."
So this means that the branch is supported until Chrome 42 goes in to the stable channel. Though a case could be made that since 4.1.0.21 is tied to Chrome 41, which is still on the Beta channel, and "Our stability expectations are the same for every branch (once it starts shipping on Chrome stable, which is roughly 6 weeks after it's been created)"
Incorrect. We support the V8 versions shipping in stable Chrome and, to some extent, onward. Per http://omahaproxy.appspot.com/ current Chrome is on 3.30.33.16, so we support that. 4.1 is not quite supported yet, but it's actually ahead of the curve, not behind.
