Apoc's forum post announcement is not an official confirmation, and there could be technical delays outside of publisher Electronic Arts' control (i.e. on Microsoft's side). Command & Conquer 3 will come out on Xbox 360 on May 10; it was released on PC late last month to positive reviews. The development team, EA Los Angeles, was also responsible for the Xbox 360 strategy title Lord of the Rings: The Battle for Middle-Earth II, whose controls were surprisingly well done for a genre that typically does not map well to consoles. Should it prove true, we're sure to be one of the first to download the demo.
[Via Xbox 360 Fanboy]