Al Jazeera's Ayman Mohyeldin has just been on air saying that there are now only "a few hundred or so" protesters in Tahrir Square and that "it is getting back to a sense of normalcy". 

He reports that vehicular traffic is now moving smoothly through the roundabout at the square.

As far as the causes of the protesters' dissatisfaction? Ayman's summed it up nicely:

One of the consistent demands of people across Egypt is that justice for many of the former elements of the regime has been extremely slow. They are extremely imbittered by those who were ... accused of being directly involved in the killing of protesters, mainly the former minister of interior and the president. Now one of the most aggravating things in the eyes of many Egyptians is that none of the senior officers of the ministry of interior have so far been brought to justice. None of them are facing charges for their [alleged] involvement in the killing of protesters. That is one of the major greivances of the protesters in Egypt. They want to see the wheels of justice spinning faster when it comes to former elements of the regime. 

"They want to see these trials in a more transparent way. Right now media is not allowed into any of these trials, and more importantly, many of the victims and their families are not allowed to attend or are unable to attend to see justice being carried out."