I've been thinking about this idea. Its true that its relevance is only till varnam gets all language support. But the rules for the stemmer too goes into the scheme file. To improve or add the stemmer in other languages we have to edit the scheme file again. For someone not well versed in ruby the syntax (all the square brackets and curlies) might look a bit intimidating. I remember soorej having difficulty reading the scheme file. So if we come up with an editor/gui tool that makes editing the scheme file more intuitive for the end user, I think it will eventually detach the burden of adding a language/stemmer support from the developer. No matter how many comments we include in the scheme file, an end user will always prefer a GUI interface to a command line one.
Also, can varnam be adapted to handle non-indic languages? I know that the database now contains sanskrit based entries like swaras and viramas. But if someone wants to, say, add support for arabic, will it need changes to the underlying logic?