Edit: To say Docker is analogous to Git for deployment fails outside of the Linux server realm (lxc). I'm trying to think of an OS-specific source control system to fix the analogy but can't come up with anything only-Linux... 'TFS for deployment'? :)
I plan to check out http://ulteo.com/home/en/download/sourcecode as an alternative.
In a previous blogpost, the Docker team outlined how LXC will become a (albeit native) plugin, just like AUFS. Running Docker on BSD (using Jails as the container provider) is certainly a goal. If you're on OS X, you could use chroot instead of full namespacing capabilities.
To be fair, this is not available today. But I don't think it's fair to say that Docker will not be useful anytime soon on those environments.
It's still quite different.