A lot of people whose judgment I respect are doing just that on their twitter feeds (I'm finally coming to understand how powerful the medium is as an aggregator of opinion and information about breaking news). The Twitter hash tag being used most often is #sidibouzid, which is the name of the central Tunisian city where rioting broke out in mid-December, after a university graduate reduced to selling fruit on the street set himself on fire to protest the seizure of his cart by the police. (Officially, it was because he didn't have a permit, though most likely it was because he didn't have enough cash to pay a requisite bribe.) A lot in that feed is rumor and should be treated with care, but there's lots of wheat among the chaff.
The usually measured Arabist says the scope of the street protests there are giving him "goosebumps." Blake Hounshell, the managing editor of Foreign Policy magazine, another man who hasn't struck me as the excitable type, thinks "Ben Ali is finished." Shadi Hamid, research director at the Brookings Institution's Doha Center and whose work focuses on democracy promotion in the Arab world, is amazed by the scope of Tunisia's protests though he does offer a note of caution that I agree with: "Algeria was on the brink of the first successful democratic transition in Arab world. Iran seemed on the brink as well."