I started to build a thing (maybe an OpenAlexa) for this reason (glider5.com) - the goal was to eventually hook it up to STT and TTS and have it answer queries, with all the code being open. Right now it kind of looks like a dysfunctional wolframalpha - but where anyone can write the code to answer queries.
Not sure whether to just kill it or do something else with it, but it was a fun idea.