Don't worry, no european leader will fly an A380, here we don't think the bigger the better, especially on these times of budget cuts and efforts asked to the population. And with the environmental concerns it would be seen as a provocation.
I'm not a big fan of the line of the A380, it's too short, but I'm not a big fan of the 747 either, with its ugly bump. I much prefer the A340-500, that's a beauty.
The French government (I'm French) has some A319 ACJ, A330 and A340, some Falcon too, and no intention to change for the moment. There is no equivalent to an AF1 here, each member of the government (and same for the president) take the plane they need for their trip.
I wonder what did you think several years ago, when Mitterrand was president and was flying around in Concorde.