Obama should declare (at least) - and soon. How he handles this will have a greater impact the Arab world's perception of the "new" US than how he unwinds Iraq. People will forgive some slips there (W's mess etc) but on Palestine, he'll be judged by his own doing. If he is true to his "principled stand" claims, it is still possible that he'll come out in favor of Israel on this (or some other) tactical steps but it is also probable that he'll have a strategic emphasis that means a move away from their historic preferences. In any case, continuing to wait is a bad option - the default setting; given the reality, perception and propoganda of decades, is not one that makes the man on the street trust the US or its allies in the region.
*Note: Like much of the problems around the middle-East (and some of the South Asian ones too) that the US is dealing with, even this is an inheritence. A classic understatement of this: "...the origins of the Arab-Israeli problem are too complicated for easy summary, but among the points normally overlooked by most of the British media is that the government of the United Kingdom bears a unique responsibility for the problem. It sold the same real estate twice. In the direst moments of the first world war Britain promised the same territory to the Jews and to the Arabs..."