According to this Eurogamer piece, Rare’s finished work on the Viva Piñata: Trouble in Paradise demo, which is now in certification with Microsoft.
“Yes, a demo is on the way,” lead programmer Will Bryan said. “As soon as possible.”
He added: “We built the demo from starting, so we’re pretty much ready to roll on it, we’ve just got to get it through certification.
“It’s from the main game, but there’s pointers to the fact there are Live features and Just For Fun mode. It’s 25 minutes of the main game basically.”
More through the link.