Something, I missed in the article, is Chrome's background in WebKit. (Rather, it seems to convey the impression that this was an original project by Google.) Anyway, this may also directing us towards a viable alternative: A new, independent and cross-platform repackaging of WebKit2 / WebCore.
Any problems with Safari?
On a practical level, it's been quite some time since Safari isn't cross-platform anymore. Also, it's fixed to a specific version of the operating system, which also applies to the open source Webkit release. I'd love to see an implementation with less external dependencies.