Obama made it clear that starting on January 20 the rules of American involvement in the region will change, and his administration will be a lot more active in pushing the diplomatic process between Israel and the Arabs forward.
Obama's timing, after the strike on the school, signals the direction the U.S. will turn in its attitude to the region: It will support Israel, but will oppose any harming of Palestinian civilians. This means that Israel will find it difficult to close the crossings into the Gaza Strip at will.
This week I made some calls to regional experts asking for their take on how Obama might approach the peace process in the wake of the Gaza incursion, and one of them, Shibley Telhami of the University of Maryland the Brookings Institution, agreed that Obama is likely to put a far higher premium on the civilian toll than had the Bush administration:
"Given how he’s tackled human rights, humanitarian issues and the kind of position he wants to take globally in terms of a signal of where we stand, it’s clear he’s going to be much more sensitive to civilian casualties," Telhami told me. "You can say we're going to go in and not repeat certain policies, do things like close Guantanamo, and not be sensistive to the kind of civilian casualties that have people demonstrate in the street around the world. That doesn't tell you what policies he’s going to pursue, but in terms of how he projects himself, that tells you something."
This is mostly speculation at this point--but also a seemingly credible analysis.