Francois Fillon doesn't need hectic introduction in the weeks to come, he's been part of the center-right (or maybe close to right-wing) for years, and he doesn't have Sarkozy's baggage (which is why the latter was rejected in the primaries of the French conservative party). Fillon has won his party's primaries, and he can immediately move on into general-election mode, because he doesn't need time to re-position himself along the political spectrum, or steal votes from Marine Le Pen like Sarko tried to do, because he's been enjoying the support of the right-wing base all along anyway - and it seems France has a lot of that these days.
I'm talking of those millions of French people who enthusiastically support his views on family, Christianity and traditional values, whatever that means.Those are citizens who are horrified by left-wing liberalism, the multi-kulti notions, gay marriage, etc. You get the idea. These voters want a president who'd show a firm hand, and restore law and order in a country that has increasingly perceived itself as threatened by terrorism and deep social change. It's essentially a reactionary, well, reaction. And Fillon is the right man (literally) at the right time and place to ride this wave.
He represents those segments of French society who are the easiest tool for winning elections. He uses rhetoric that heavily relies on creating an aura of national unity, describes Islam as a hostile external influence, and glorifies French values and tradition.
Lots of French people dream of a president who'd embody the strong figure of a unifier and savior, along the post-war model of Charles de Gaulle. It's the same nostalgia of the past that has made the Brexit possible, or Trump's election (make America great again, remember?) There's a certain longing for the days of yore behind all this, an imaginary Golden Age if you like - with all the established limits and boundaries, clear-cut values and categorical definitions, a longing for a time when the white man from the rural areas (and I do mean mostly man) was calling the shots, and felt like they were the master of their own country. These folks have felt their country slipping away from them ever since - hence the reaction. Such political notions are conveniently pushing wind into the sails of right-wing populist authoritarian politics. And this process will be accelerating in the following years.
Fillon is quite blunt on the latter point: he doesn't hide his intention to bring "radical treatment" to France, a la Margaret Thatcher. By the way, Britain has yet to fully recover from her policies - even today, after so many years. Let's hope the French presidential front-runner would come up with more intelligent solutions.
Unlike the Front Nationale, Fillon is not opposed to a united Europe. But just like Marine Le Pen, he holds cordial sentiments for Putin. This "bromance" between Kremlin's master and the French conservative may seem inexplicable, but if he's to become president, Fillon could actually undermine Merkel's policies that have attempted to counter Putin's expansionist aspirations. I.e. Russia will have yet another major Manchurian Candidate leading a powerful country, apart from Trump.
As for the migration crisis, Fillon is more of an opponent rather than partner to the EU on that issue. You can't expect much solidarity from him there. So we could say the best thing that could be said about Francois Fillon at this point is that he'll probably be able to defeat the FN, which makes him the lesser among two evils. And that's all. Everything else that we've heard from his campaign so far doesn't promise anything good for liberal democracy in Europe.