A few years ago, some high profile organizations (W3C, Adobe, Facebook, Google, Hp, Intel, Microsoft, Mozilla, Nokia, Opera) came together to try to help standardize the web platform [1](Javascript, CSS, HTML). That was a HUGE failure - because it was driven by business rather than developers. How will the "Javascript foundation" do better?
I don't see how WebPlatform was about standardizing. The standards bodies already exist: W3C (with its various WGs), WHAT WG, TC39. The main goal of WebPlatform was to provide a consistent documentation for all standard web technologies -- which largely relied on volunteer work and competed with existing solutions like the Mozilla Developer Network (despite Mozilla supporting the project).
I don't see the JS Foundation being even remotely related to this. The JS Foundation is pretty much just a small Apache Foundation for JS projects. And it's not new: it's mostly a rebranding of the jQuery Foundation which has existed for years.
It's also decidedly not the "JavaScript Foundation". They don't have the trademark for JavaScript (I think technically Oracle still holds the JavaScript trademark with Mozilla having an unrestricted license to use it). It isn't affiliated with TC39 or any standards body and it doesn't steer the development of the language.
IMO the name is unfortunate unless they extend the scope beyond "we support a couple of open source JS projects".
Uh. That's a documentation site - basically a wiki. It didn't exactly catch fire, but it wasn't trying to standardize anything and it didn't fail to do so.
[1] http://webplatform.com