A lot depends, I would say, on how "centrist" Hollande becomes in order to woo Bayrou voters in the Parisian bobo set in the event things tighten up a bit between now and May and in so doing seperate himself from Sarkozy in the first round. Some of the folks on my side of the spectrum would vote Mélenchon as a result, instead of Hollande, especially considering Hollande's presence in the second round is probably more or less assured in any event (though the same cannot be said of Sarkozy). We're all over the debacle of 2002, Besancenot is keeping the sort of comfortable low profile one can afford one's self when one's wife makes 10K€/month, Arlette is retired and all the other extreme left figures are walking dead people, Poutou and Arthaud polling at 1% or less, and I doubt they'll share as much as two percent of the general in the first round. So, Mélenchon is the only credible left alternative to Hollande (the Greens and especially Joly too ideologically heteroclite to be properly refered to as left), and so a Mélenchon vote is a natural and safe one for voters on the left. Indeed, one of the uncommented points in this election so far is that the left, after having tried and failed to properly unite in 2007, instead seeing seperate Besancenot, Laguiller and Buffet candidacies, has finally done so.

I'd bet money he comes in close to 10%, pehaps more.

Chevènement is a wild card, and here I agree with your implication that he is unlikely to actually run, adding to this observation that he polls quite poorly (under 2% on everything I see) and is not quite old (he'll be 73 on election day).

One final comment. While in the past the PCF, now a critical part of the Front de Gauche, have gotten their seats via maintenance of historical "fiefdoms," this is beginning to change, a notable exception (and harbinger of hoped-for future developments) being the rise of André Chassaigne, Mélenchon's opponent in the united left primary, whose base is in political terrain not particularly warm to the PCF (rural Puy-de-Dôme). Another example would be Michel Le Scouarnec, elected in these recently past senatorials in similarly not-particularly-friendly to PCF Morbihan.

And, of course, we have not yet really seen the full impact of the Europe-wide "bankers first" austerity. I am sure things will become more interesting as 2012 and the rest of the decade progresses, regardless of how well Hollande governs.

 

The Hun is always either at your throat or at your feet. Winston Churchill