What happens when you take the one dumbest data format in existence, extend it (I won't even go into that), stuff it into a centralized server, and let people manipulate it concurrently, using a TECO-ish differential editing protocol?
Answer: Google Wave.
Of course to make that work you have to look into CSCW which hasn't produced any interesting results in 40 years, and adopt silly bean-counting technology (ha!) like Operational Transformation. Only so that text-editing works in your system.
Joel doesn't understand that stuff. Heck, not even Manuel does.