I don't understand why they're even offering a download. If I'm using a Mac and I want to start using git for the first time, chances are the pre-installed git (1.7.7.5, from last December) is the best option.
Git isn't "pre-installed" on OSX; it comes with XCode. You can be a developer on OSX and not use XCode. It's not common, but it doesn't hurt to offer a download. And, of course, it's not like XCode gets updated every time Git does.
