Here's the demo, where you can edit some canned texts (but not actual Wikipedia articles, yet):
http://www.mediawiki.org/wiki/Special:VisualEditorSandbox
Post bugs here:
https://bugzilla.wikimedia.org/enter_bug.cgi?product=MediaWiki%20extensions&...
And here's the blog post, which puts it more in context.
http://blog.wikimedia.org/2011/12/13/help-test-the-first-visual-editor-devel...
This new editor was mostly written by Trevor Parscal and Inez KorczyĆski, although lots of others have contributed. I've sat a desk away from them for a few months and I have to say I'm extremely impressed with what they've put together. If you're expecting Google Docs, we're not there yet. But the basics are starting to solidify, and it's getting easier and easier to add cool features.
Hey MediaWiki developers, surely you're not going to let Trevor and Inez have *all* the fun?