Thanks! Your point was one we expected to hear, especially here on HN.
We actually did look into getting Mercurial (which is what we use internally and what we provide via Kiln) up and running in AppEngine, which has been done before, but was just beyond the scope of the first phase of the project.
And I agree, I don't think we'd ever host FogBugz's or Kiln's CSS with it on AppEngine, but I do really want to be able to use the editor and SCSS with those projects, so we'll be keeping an eye towards making that more natural.
We actually did look into getting Mercurial (which is what we use internally and what we provide via Kiln) up and running in AppEngine, which has been done before, but was just beyond the scope of the first phase of the project.
And I agree, I don't think we'd ever host FogBugz's or Kiln's CSS with it on AppEngine, but I do really want to be able to use the editor and SCSS with those projects, so we'll be keeping an eye towards making that more natural.