The site states that it is this:

Zero-bullshit, single–command, bring your own source control web publishing CDN.

On the blog post it reveals a bit more interesting information, imho.

Existing publishing solutions such as Github Pages and Amazon S3 were developed prior to the recent changes in client-side web development practices and thus didn’t have front-end developers in mind when they were built. These services leave a lot to be desired when it comes to deploying static web projects.

Now I expect to find what it can do beyond gh-pages, etc. And that's what it says.

With surge you effortlessly get things like…

  • Custom 404.html files.
  • Catch-all 200.html files (for PushState apps).
  • SSL.
  • Indifferent (intelligently) about trailing slashes (“/”).
  • Clean URLs (indifferent about trailing .html).
  • Far-future expire headers.
  • Easy collaboration built right in.

To me all this seems like something that gh-pages can do too, it just requires a bit of setup. What do I miss? I guess I just expected much more :).