If it's being revealed at Toy Fair (February 13–16 in NYC) and it has "broad appeal," expect it to be some kind of children's game. Activision recently unveiled Squinkies for DS (pictured), which fits the "toys" (it's based on a popular toy franchise) and "broad appeal" classifiers, but not the "unprecedented" online integration, making it unlikely that the DS game alone is what the report is talking about. it's possible that this new game will use the Squinkies license, though, since Activision has those rights. Rest assured, Joystiq will be at Toy Fair to find out more about this mystery project.
Update: And the answer is ... a new Spyro game, with interactive toys!