It turns out that running your own Feature Server isn’t that complicated. Get a Drupal site. Install the fserver feature. It’s most exotic requirements are Filefield and Context, and context is just their to facilitate easy block placement of release information.
All the feature really does is provide a fancy XML Views style plugin, a couple content types with their CCK fields to specify things like version information, and some special file-handling magic to push files and tarballs around.