in no particular order:
 * Take advantage of Bryan O'Sullivan's bytestringparser
   library, to move internals to ByteStrings for efficiency.
 * Take advantage of network-bytestring as well.
 * Enhance IPluginT monad, most likely by writing our
   own instance for it, rather than letting newtype 
   deriving do all the work for us.
 * Plugins. Many more.
 * Write a more proper 'plugin library' that will
   allow controlled access to resources like
   utilities, processes, files and the web.