You're about to start a civil uprising to overtake a corrupt government. Everything is ready to go but you have no idea what concessions would maximize the likelihood of permanent and lasting change.
This article in the Financial Times has the answer.
According to the economists Daron Acemoglu and James A. Robinson, who have built a detailed series of game-theoretic models of political transition, the answer is: ones that cannot be easily undone. Tunisia’s Ben Ali will surely not return, but already activists are concerned that democratic reforms may not be entrenched, and have returned to the streets to protest. Mubarak may be Egypt’s past, but Egypt’s future is unclear.
A fresh constitution, civil rights, and credible elections are all ways of safeguarding the gains so far. The revolutionary protesters are right to insist on them; it would hardly be a surprise to see feet being dragged by those who profited from the status quo.