I dunno. Currently there is really no obvious successor for Merkel. Von der Leyen is probably too polarizing, we'll see how she'll do in the Ministry of Defense, just because she produced an army of children doesn't mean she can manage an actual one, with all the problems the Bundeswehr has. Like 10 years ago I would have thought of Wulff as a potential successor, but we all know how that turned out. I think the CDU might have to move a little back to the right in the future, to not disenfranchise their voter base.
The SPD lacks a potential chancellor too, Steinbrück was a compromise, he was never reallly accepted by the left wing of the party and in 2017 he'll be too old and probably too tired of politics. Gabriel lacks the charisma and Steinmeier isn't gonna try again. Not sure if the SPD is gonna be more centrist, they'll have the problem of distinguishing themselves as a minor partner in the coalition.
The absence of the FDP in the future might make things interesting. They probably could make a comeback, since they still have a voter base and market liberalism isn't represented much currently, but 4 years is a long time and they'll certainly get less votes if it looks like they're not gonna make it.
The Greens will have to fill in for the FDP on occasion (except in economic policies obviously) and maybe that's where their future lies, now that they don't have any more issues they "own".
At least I don't think there will be a red-red-green coalition in 2017, Die Linke is still not a party one can govern with. Since there was an actual right-of-centre majority in the election that is not reflected in parliament and won't be in terms of policies, it will be interesting what happens with the AfD. They might of course dissappear quickly, but if they manage to stay on course not getting taken over by far-righters and if the other parties stop branding them as extreme, they too could fill the hole that has been left by the FDP (and by the right wing of the CDU).