I think it's interesting here to look at Barack Obama's past on this issue. Before he ran and when he ran for the Illinois State Senate he was pro-Palestinian, when he was a State Senator, he still was pro-Palestine, but as soon as he became a full federal Senator, all of a sudden he became pro-Israel like the vast vast majority of the rest of the American political scene. Of course, he had higher aspirations than the US Senate and without a somewhat pro-Israel stance, whereby he can appease the likes of AIPAC and other pro-Israel groups, he would have no chance getting anywhere. Without a pro-Israel viewpoint, he'd have probably have found it hard to be re-elected as Illinois's Senator, far less becoming the President. It would also be worth noting of who his Vice President is. Joe Biden has even said himself that he was "Israel's greatest friend in the United States' Senate". This was just another move to show that Obama does indeed share a viewpoint with the majority of Americans, which in turn, helped him along the way.
I think underneath it all, Obama is not half as pro-Israel as he proclaims to be, and not a patch on the stance of his predecessor. Of course though, without this stance, he wouldn't get very far in his political career.