Earlier quoted context omitted.
Don't worry, we do intend to share the data publically once it's all in.
given that there is no stated end date to this experiment, when exactly will you post the data? ("once it's all in" doesn't say anything). will you post all of the data (in its original, unadulterated form) collected for free, unrestricted download by anyone for any purpose, including competing with last.fm? intending to share, and actually making a public promise to do so, are quite different things.
The exact details are out of my hands -- I'm just a tech guy -- but we're active members of the music information retrieval community and always have been.
No-one even knows if it's possible to crowdsource good enough BPM data like this yet, so even demonstrating that it's feasible would be progress :-)