Logo is not responsive

Yes it is, but its always relative to its containing element size - which is the header, which is 100%. The default CSS for all images is max-width: 100%, so the image will always try to scale to its maximum dimensions, in your case 200px wide - and as you found out when the screen is more than 200px the image will be it's normal full size.

The way to get the logo to scale is to write some CSS for it, and place it in the responsive stylesheets. For example you might use the responsive.custom.css file and something like this:

@media only screen and (max-width: 480px) {
  #logo img {
      max-width: 100px;
  }
}

I don't know what you're vision for at is Jeff, but bundling a responsive image module the same way you've done with fontyourface to handle these kind of things might not be a bad idea for the future. Again as an unchecked extra option.

http://drupal.org/project/ais is great, I use this, but it requires htaccess rewrite though
http://drupal.org/project/cs_adaptive_image
http://drupal.org/project/resp_img - heard v good things about this, not had chance to fully investigate
http://drupal.org/project/cs_adaptive_image

So many possibilities.

Yeah, many possibilities however they are all (last time I looked seriously) in a state of development and heavy flux, so its really hard to nail down something that's not a 100mph moving target. Fontyourface is pretty settled and highly usable with an API I could rely on and hook into easily, these other modules I am not so sure.

For sure I will look again, they are very powerful and extremely useful, Attiks http://drupal.org/project/resp_img module probably has the most heavy development and is pretty easy to use, this guy is a machine coder and does great things.

Looks like there is a successor to resp_img, which is picture, which even has a upgrade path to Drupal 8.