The title says it all, really: Google's big developer conference is coming again to the Moscone Center West in San Francisco on April 24th-25th, 2012. Google says a million people participated in this year's I/O, and the company used the time to show off Music Beta, Android @ Home, the Chromebox, the Galaxy Tab 10.1, and Ice Cream Sandwich. It's still too early to register for the conference, but you can put a big circle around those two days in late April.