* Take the the channel's URL as enclosure_url and make enclosure_url an optional parameter
* In verbose mode, log warnings to STDERR for all the opinionated decisions and fallbacks that Dropcaster takes
* Allow overriding the path to the ERB template (and document the available template variables)
* Support a tree of iTunes categories: <itunes:category text="Technology"><itunes:category text="Gadgets"/></itunes:category>
* If an index.html.erb is present, generate an index.html from it
  ** In addition to that, if an item.html.erb is present, generate individual html for each item from it and link to it from the index.html
* Print warnings when one of the specs from http://www.apple.com/itunes/podcasts/specs.html is violated
* Allow muting of the iTunes warnings (see above) using a commandline switch
* Implement sidecar files
* Support other file types than mp3 (e.g. ogg or pdf)
* Treat lyrics as plain text for the episode page, and with an optional command line switch we could also support markdown etc.
* Potential optimization for large numbers of mp3 files: If there is an existing index.rss file, do not re-read the information from those files that are still there and still have the same hash value.
* It feels pretty awkward to refer to the ID3v2 frame names all the time. After all, this is an implementation detail. Maybe we can wrap the frames with a nicer name, but still allow access to the underlying mp3info library? Maybe all we need is some aliasing and / or delegation?