I really like the concept, and it fits in with a bunch of techniques we've been using at work in line with the "Big Visible Charts" ideas. Things like this and Agile stories written on index cards and pinned to the wall do sound hokey. A number of people like Johanna Rothman http://www.pragprog.com/titles/jrpm however point out, that these techniques are a lot more inclusive and (as I've found) you get much more animated discussions than the pm/architect/team lead writing a document "for discussion."
If nothing else it's fun to watch management trying to cope with your walls being covered with sheets of paper, cards and string when they've paid all this money for MS Project and the Rational Suite.