The Web site found out that Kaarbo Design, the company that created many graphics for the original Forza Motorsport, listed Forza 3 as one of the titles it has worked on. You can see the screenshot they nabbed in our gallery below.
TeamXbox says that this "leak" could be even more evidence that Turn 10's "next big thing" is in fact Forza 3. Of course, this could all be nothing. Maybe a typo? The posters at Forza Central have Forza 3 logos on them, though.