io.js intend to take V8 releases as quickly as possible. This is great because io.js will be able to take on any new features available in Chrome and will also avoid any lingering bugs.
A lot of different companies and individuals use Node.js. Unfortunately, until recently, only one of these really has had a say in what happens with it - Joyent, the corporate sponsor.
io.js intend to work under an open governance model with the aim to be as transparent and to work off of a consensus. This works in everyone's favour as the technical committee will be working to push the technology as a whole forward, rather than things that may benefit the corporate interests.
Already io.js is seeing an uptick in community participation. At the time of writing, the logo ideas thread has over 430 comments and has only been open for 3 days. Couple that with the active development going on in the v0.12 branch and you can see that the community is enthusiastic about io.js.
In his post on Medium, Mikeal addresses some concerns about fragmentation, including fragmentation of effort. In his last paragraph about fragmentation of effort, he says:
I don't see this as a zero sum game, we aren't dividing the entirety of potential effort between two projects, we're increasing the overall effort being put it.