Honestly the movement needs to be organized in such away that it is not about a single day or single moment. Advertising that you will come out in masses on a certain day, only helps the govt secure its forces in key areas and kind of shows your hand to the opponent.
What needs to happen in order for the movement to get beyond just riots and scrimmages between the police and the people, is to branch out the struggle to different dimensions. That way you put enormous resources on the government to control everything and they just don't have the numbers needed to do this.
The Green movement needs to have a process where on a daily basis the government is under constant pressure. There needs to be massive strikes. Sabotages that cripple government owned institutions. Blackout, delay of services, military style attacks on IRI forces (I mean amalkardeh chiriki). You can not win against a ruthless regime through none violence means. Iranians across Iran need to cripple the base of these guys and that is their source of money revenue. Those that lived in Iran during the Revolution and early years of war, remember the daily strikes, the unions that took to the streets and the net effect was that the government simply could not afford to continue its liberal waste of money on paying their goons.
The outside Iranians should put pressure on western governments to continue putting restrictions and heavy sanctions on those institutions that we ALL know support IRI. If international sanctions take a foothold IRI is toast for sure. Iran is almost bankrupt. This may come as a surprise to some, but the country is in dire need of money and stopping sale on it's ONLY source of income (OIL) will bring down these guys faster than any other idea you may think of. I am absolutely convinced, if the movement in Iran becomes a mass demonstration/strike movement and shows a comprehensive POPULAT NATIONAL movement, countries like Russia and China will not be able to afford doing business with such a regime. Not that they give a shit about the people, but it just does not look good for these two to be the sole supported of a country that the world sees as an oppressor (i.e., South Africa of the 80s).
Overall, I think we need to broaden our outlook on the movement and realize that a mass gathering of people on a single day is nice for 10 minute sound bites, but will not be an effective long term plan.