Planet F1 report a likely change to the Monaco GP date.

"Although the official calendar of the 2010 F1 events is not yet published by the Federation Internationale de l'Automobile, we strongly consider that the original dates of the 68th Grand Prix Automobile de Monaco announced will be advanced 13th to 16th May 2010, Ascension Day," said a statement from Monaco's sporting body the ACM

Article: http://www.planet-f1.com/story/0,18954,3213_5628762,00.html