<<Has any popular git hosting site added mercurial support?>>
Yes. In fact Github implemented the Git plugin for Mercurial that lets you use Github (or any Git repository) with Mercurial as your client rather than Git.
The problem I have with git isn't in its syntax. It's in more central decisions with which I disagree fairly strenuously (I am very strongly in favor of indelible history, for example).
Git history is indelible too. I mean, you can't mess with an existing tree without it being obvious.
But in any VCS you can of course start over. Set the system clock back and check the existing code from another repo into a new one in different chunks making it appear to have been made differently in the first place. There's no way around that other than signing your commits which would work in git as well...
Yes. In fact Github implemented the Git plugin for Mercurial that lets you use Github (or any Git repository) with Mercurial as your client rather than Git.
I guess this shows which DVCS is winning?