This would be an excellent application of the Slant [1] concept. Basically create a topic which is the idea, with sub topics for the other columns and then debate them. Then layer on a searchable UX so that different concepts could be tagged and located and correlated. Boom, community curated web site of startup ideas with history.

[1] http:://slant.co/

(I personally have nothing to do with Slant just find it an interesting way to capture a debate like the ones in the spreadsheet into a more structured form)