Answering Carrol's specific question isn't really possible for those of us under the age of 40, since we lack the necessary long-range perspective.
However, I will say this as someone whose youth coincided with the Seattle-Porto Alegre-Genoa wave of movement: this current wave is far more important than that one was.
That whole movement -- incorrectly characterized as "anti-globalization" by the bourgeois press and media -- represented a necessary and appropriate regroupment of forces inspired by the Zapatista rebellion in Chiapas and other things going on at the time, and was notable because of the reconciliation between the so-called "new social movements" (environmentalism, queer and feminist movements, third world solidarity and anti-racist movements) with the traditional labor movement constituency of the left, understood in the sense of trade unions and traditional social democratic and (post-)communist parties.
However important that wave of movement was, it basically represented merely a stirring of professional and semi-professional "activists". That's not intended as a diss; it was important for the constituencies of the left to demonstrate signs of life after the hangover of 1989, but ultimately it was a regroupment of forces.
What is far more important about the current wave, I think, is that it represents a real radicalization of people outside of traditional activist constituencies, drawing the support of a wide layer of society beyond the confines of the placeholder "left", however we understand it. And by the current wave, I mean not just the OWS, but everything from Wisconsin to Greece to the indignados in Spain to the Arab democratic revolutions.
I encourage people to read Mike Davis' article in the December New Left Review, I think is characterization of 2011 as "our 1848" is right on.