Developers at Lucid Games, formed by ex-Bizarre Creations staff two years ago, appear to be on the verge of announcing a new project possibly at this month's Xbox Reveal event where Microsoft are set to unveil their next console.
The studio's official Facebook page recently commented "So yeah, mid-May will be interesting for the studio. We have some exciting updates coming. Stay tuned!"
Mid-May may well relate to Microsoft's event on May 21st. On the same day as the Facebook update they also re-posted the image at the top of this story which suggests at least part of their game will be set in London. Given the origins of the studio it's quite possible they may be set to announce another Project Gotham Racing, which Microsoft owns the rights to.
The original Project Gotham Racing title was an original Xbox launch game and became the second best selling game on that console behind Halo: Combat Evolved. The game was a spiritual successor to the Dreamcast's Metropolis Street Racer.
It has also been suggested that the next Xbox will launch with a new Forza title.
Source: VGLeaks.