I also trust the weekly mouseplanet updates as well as the DL calendar.......Here it is from this monday. It's showing matterhorn closing but no word on california screamin' yet.
Disneyland
Main Street Mad Hatter closed until June 30 for refurbishment and expansion.
Fantasmic! dark June 17 - June 28, 2006, for activities surrounding premiere of Pirates of the Caribbean: Dead Man's Chest.
Sailing Ship Columbia closed June 17 - June 28, 2006, for decoration and then removal of decoration related to premiere of Pirates of the Caribbean: Dead Man's Chest.
Matterhorn Bobsleds closed August 28 - November 22 for complete refurbishment.
Haunted Mansion closed September 5 - September 28 for installation of Haunted Mansion Overlay.
Disneyland Railroad closed September 18 - September 22 for unknown reasons, probably general maintenance.
Finding Nemo Submarine Voyage is currently under construction and will open sometime in 2007.
Disney's California Adventure
Francis' Lady Bug Boogie closed June 17 - July 13 for general maintenance.