This is an interesting concept--get 20,000 people to occupy Wall Street with one simple demand, to be determined. But I'm just not sure how effective it would be--Wall Street would claim they don't have any power, and I'm not sure how much actual power for change they do have...it seems to me (in my ignorance of all things financial) that it's mostly a system-propagating machine, and has little revolutionary potential even if people on it would listen to such demands.
Also, "End the Corporatocracy" is not a demand. It's a slogan. It's a command. But. Not a demand. As several commentators identify, good and achievable demands are very, very specific, not prone to twisting, not prone to evasive answers. "Mubarak Must Go" is a good (utilitarian) demand. No More Taxes is also a utilitarian demand, although I can't bring myself to suggest it is good in any way--clear, concise, exacting.
But what would be a clear demand? One of our current political problems is that none of the issues can be summed up in a sentence, without a lot of qualifiers. "Make sure social security is there for me, and for my grandparents, unless they are already billionaires" is not a very good crowd-chanting expression. "More Beer Now" is clear but useless...
If we could change just one thing, one crowd-chantable concept, as a result of a mass action, what would you vote for? I'm going to think about it and post my answer later. But I'd love to hear other thoughts!