At the Monterey Bay Aquarium, "The Jellies Experience" opens March 31, 2012. The aquarium that pioneered displays of the elegant ocean creatures 20 years ago says their newest exhibit will feature "will feature 16 species from around the world: from crystalline comb jellies that pulse like living rainbows to improbable flower-hat jellies with magenta and chartreuse highlights on transparent, pin-striped bodies; from elegant Japanese sea nettles to upside-down jellies; from a room that immerses visitors in a living moon jelly swarm, to exhibits of fluorescent jellies and Day-Glo corals."
In San Francisco, the big, upcoming event is the Americas Cup yacht race, which will be held there in 2013, but preliminary races for the big event begin in 2012 with two back to back events: August 11 to 19 and August 27 through September 2. Details are here.
Also in San Francisco, Inn at the Presidio, the first hotel in the former military post will be the city's only new hotel for the year. It will welcome the public beginning in April. Visit their website to get a preview.
You'll have to wait until at least 2013 for the opening of The Wizarding World of Harry Potter at Universal Studios Hollywood.