A lot of commentators have been highlighting - often approvingly - the absence of a significant Islamist role in the Tunisian protests so far. See for example here, here and here. Many of them have been arguing that, thanks to the repression of political Islam in Tunisia, its high rates of education and the large middle class, political Islam is not and will not become a significant political force in the country, and that this is a positive thing as Islamism is a bad thing and/or inhibits democratic development, whether because Islamists are undemocratic or anti-Islamist foreign powers interfere to block democratically-elected Islamist governments.
I don't want to get into the argument of whether this would necessarily be a good or bad thing in this post. However, I will argue that it's much too soon to count Tunisia's Islamists out. No, they don't seem to have played a major role in the protests, though it's not really clear that any party or major organisation did either. The UGTT trades union was fairly prominent, but then the UGTT trades union, unlike the main Islamist movement Ennahda, wasn't banned under Ben Ali, and its members weren't largely in jail, exile or under constant police surveillance. From what I understand the largest component of the thousands of Tunisian political prisoners under Ben Ali were Islamists; I'm not sure why he would have gone to the bother of repressing and jailing them if they were a marginal force.
Leila Ouardani argues that the 1989 elections - the most free in recent decades - demonstrates the lack of support for Islamism in Tunisia because Ennahda only won 14% of the votes cast. I'm not sure how relevant elections from over 20 years ago are to the situation today, but I would argue that the 1989 results looked at in their full context suggest, if anything, that the Tunisian Islamists were at least at that time a serious force to contend with. Firstly, the elections may have been the fairest in some time but they were still held under conditions that greatly benefited the RCD while disadvantaging opposition parties (see Chapter 2 of Christopher Alexander's recent book for more details), suggesting that the opposition parties' vote would have been higher in fair elections. Secondly, the Islamists were particularly at a particular disadvantage, as Ben Ali refused to legalise their party before the elections, meaning they had to run as independents.
Despite this significant additional disadvantage,which undoubtedly damaged their ability to campaign and organise, the Islamists still won vastly more votes than any other party than the RCD; the next most successful party took 4% of the vote. At the very least they were the most important opposition force by far, and possibly the most popular political force in the country.
Of course, having been so comprehensively repressed in the years since, they're starting from a much weaker positions than movements with intact organisational structures. Still though, from what Prime Minister Ghannoushi is saying, they may have six months to organise a campaign for the parliamentary elections (they've said they won't put forward a candidate in the Presidential elections), and they are much less tainted by involvement in the Ben Ali system than most established parties in movements; many of the legal "opposition" parties effectively acquiesced in its rule, and often defended it from criticism, as the price for being allowed legal status and occasionally a few token seats in parliament. Furthermore, if there's one thing that Islamists have demonstrated across the Middle East and North Africa, it's that they often tend to be the best organised and most highly motivated of all parties and movements, and that they have the ability to massively outperform expectations and win crushing surprise victories (eg Hamas in 2006), sometimes seemingly out of nowhere (most notably the Front Islamique du Salut in the 1990 elections in Algeria). Those who argue that Tunisia is too "middle class" to vote Islamist might want to look to Turkey for example, where the AKP derives much of its support from a newish commercial middle class, sometimes termed the "Islamist bourgeoisie."
I don't mean to argue that the Islamists will inevitably win, or even do particularly well, in any free and fair Tunisian elections, should they take place (a big if). If there's one thing that people (and above all professional commentators) should take home from the events of Tunisia, it's that noone knew what is that Tunisians want. Prior to Ben Ali's overthrow it was a truism that Tunisians were willing to trade off their civil and political freedoms in return for prosperity and stability (again see Tunisia specialist Christopher Alexander's book, in which he makes this argument), something that in my view clearly turned out to be untrue. While some commentators and journalists have suggested that the bargain was real but went sour because of recent economic troubles, these haven't been anywhere near drastic enough to prompt a sudden about-turn in the national mood; despite all the commentary the economy about inflation and a lack of jobs, the econoymhas continued to grow in recent times, including in per capita terms, while inflation and unemployment aren't particularly high by either regional or recent historical Tunisian standards, meaning they fail to explain why such a turn of events should have happened in Tunisia now. Rather, the clear explanation is the the "bargain" explanation was wrong all along, that Ben Ali and his family have been widely despised for some time and that people were simply too afraid to articulate their feelings until a sort of tipping point occurred.
So I don't pretend to know what Tunisians really want; noone can know what millions of people want and believe without solid research and evidence in the form of things like reliable opinion polls, which don't yet exist in Tunisia. But given the evidence of Tunisian history and regional precedent, counting the Islamists out of Tunisia's future at this juncture is seriously premature, and the predictions based on doing so should be taken with a large dose of scepticism.