At one point the XFMG RSS feed wasn't re-implemented after upgrading to XF 2.0 but we added it back.
Not entirely sure what's going on here yet at first glance but it doesn't appear to be functioning correctly.
Most media indexes, be that the main one, categories or albums should support displaying an RSS feed by adding index.rss to the URL. Putting the actual URL to the media index should also allow most RSS readers to find the correct RSS URL automatically.
All of the RSS indexes are only displaying one item so something is clearly not correct here. We'll take a look at this.