I know users are using Travis-ci to automatically build when there are new commits in master and push back the results to the gh-pages branch with a lot of success.

Github pages is so cheap and easy it is the disruptive technology that is eating the lunch of stand alone hosting. Users don't think about servers, deployment or other things, they simply are pushing a branch and poof it is on the web.

Do you have a wishlist of features to add to GitHub pages? Maybe allowing minimal sandboxed server side computation with a max runtime of say 1ms, setting headers, redirects or other stuff? I am guessing every little addition would eat away at the alternatives.