Just had a quick look at twenty eleven - sweet but to be a 'good' default theme and to encourage creation of child themes off of it, a couple of things would be desirable:
1) that image is SO large - pushes everything else below the fold - suitable for home page only. Other pages should have a template option without the image.
2)A one click option in wordpress settings to have NO COMMENTS AT ALL, and then have the themes know that absolutely NO mention of comments should be made at all.
There does not seem to be a way with current settings options to totally switch off all mention of comments.