His most well known activity was his still not fully revealed involvement (he denies any wrongdoing) in the CIA rendition of two (innocent) residents of Germany.
I think still it is suspicious, that Kurnaz was freed so shortly after the gov takeover. If Steinmeier really hasn't had his hand in it, then he didn't want to make a decision. The case was know well enough, that action from the top wouldn't have been unusual.

Thus just last week, a popularity poll of politicians showed him ahead of Merkel for the first time.
I'm nearly 100% sure, that the reson for this was the more atlanticist line of Merkel in the Georgia conflict and the more Russophil position of Steinmeier. Usually such issues are forgotten within ~100 days, if there is no follow up. So it depends on the question, if the conflict deescalates or remains critical.

Was there so far a comment or diary on the ARD-Roth/Putin "censorship scandal"?

Steinmeier and Munte  

• are not going to work together with the left party
  
• will keep frogs (friends of Gerd) voting for the SPD, which otherwise might have switched to the CDU, so probably left-of-center parties will keep the majority
  
• will lose some people on the left end of their party spectrum to the left party

So the most likely outcome for the next election is another grand coalition, as I guess CDU + Linke > 50%, which, with the SPD refusing to work with the Linke, means Merkel will remain chancellor, no gov against the CDU possible.
CDU + FDP < 50%, CDU + Gruene < 50%, so no other two party coaltion except grand coalition possible. This of course assumes that the SPD remains some harmony. If the SPD continues her inner party disputes, one of these two party coalitions may be possible.
Traffic light and Jamaica seem unlikely, because FDP and greens probably both would ask for rather significant influence - which is not easily possible in a 3 party coalition to provide.

Of course before the election SPD and CDU will battle somewhat, but after the election they will say, the last 4 years weren't so bad, so more of it isn't the worst which can happen.

Der Amerikaner ist die Orchidee unter den Menschen
Volker Pispers