But seriously, the Obama administration seems to be giving him a lot more flexibility when it comes to the Middle East (which they didn't allow Hillary to get too involved with)... and Kerry is certainly taking advantage of it.
Kerry also supposedly is desperate to get something done on Arab/Israeli peace for his legacy as SoS, whereas Clinton wasn't as fixated on it. Clinton was also seen by many as being more "pro-Israel", whereas Kerry is reportedly more interested in pressuring the Israelis to make concessions.