The Whiteboard UPDATE -- SURPRISE EVENT: Obama made an unannounced visit to Arlington National Cemetery for a Medal of Honor ceremony -- which the White House just left off of his schedule today. This was Obama's first wreath-laying as president of the United States. -- Carol E. Lee (2:35 p.m.) COMING UP -- ROBERT GIBBS: Will he be asked... 1) How much of the president’s original proposals need to be included in the final budget for the White House to consider this a victory? Is he willing to compromise on cap and trade? 2) Why didn’t Reuters or any of...