The underlying problem with French football is money, there are only 2 clubs with even two penny's to rub together... Lyon are a complete mess financially and their performances on the pitch have suffered come their total lack of ability to replace players, Lille and Montpellier, while recent champions actually remain pretty small clubs and Marseille are not the team they were.
Personally I don't see it getting any better for French clubs, if reports are to be believed then Hollande's tax plans for the 'super-rich' could see the tax bill of some clubs triple (becuase French clubs pay tax for all their players), something that is quite obviously going to affect them in a market place they already can't compete in. When PSG were taken over it was suggested that their money would filter down though to the other clubs, but that really hasn't happened.
I don't think it's all bad news for France, they still have a very powerful youth set up with some great prospects coming through (look at their U20 world cup winning team) and the Monaco / PSG thing might still work in their favour but it doesn't look good, for me they need to do a lot to even hold their position as the 5th best league in Europe, Portugal has been steaming past them in European competition in recent years and the Ukrainian league in particular is making huge strides, both in Europe and domestically, still will be vey interesting to see what happens.