Sad to say that Apocalypse might be the last Motorstorm because I just read their new game is more on-road than off-road. Apparently they tried proposing a spin-off of Gran Turismo but was told not to proceed by Sony Japan/Polyphony Digital. The link hints at an arcade racer as they've just hired a bunch of Blur devs after the team got let go by Activision and also the Wipeout devs from Studio Liverpool. Looks like they've got a big team for the next racer, hope it translates into a great game.
NINJA EDIT: Misunderstood the article a bit and have edited post accordingly.
Still, they should announce new game between now and E3 inclusive.
SHEEP, SHEEP, SHEEP! It's OVER! Never again will the day's of old return! Wish upon a star! Mods, Please clean up the dust bunnies around this forum. My allergies can't take it. Sneeze, cough!