Wolfram Alpha, the “computational knowledge engine” that has been the buzz the last few days uses MusicBrainz data! Click on the source information link on their example search for music:
When was Like a Rolling Stone released?
They use our data, but unfortunately they are not our customer. 😦
MetaBrainz Blog 
While I naturally applaud any use of MusicBrainz, I can’t help notice the disclaimer on their sources page:
“The inclusion of an item in this list does not necessarily mean that its content was used as the basic for any specific Wolfram|Alpha result.”
Has anyone tried contacting them for more info? There’s a link at the bottom of the page.
If they did ingest MusicBrainz, they did so fairly poorly at the moment – for instance, I can’t seem to get “Big Yellow Taxi” to resolve to anything which isn’t financial.
Kudo’s on the potential, but it seems to overpromise quite a bit at the moment.