Sony has decided against releasing the game at this time out of respect for those affected by the recent tragedies.
"We are shocked and saddened to see the impact of the earthquake and tsunami in Japan and our thoughts are with all those affected, including our colleagues within the Sony family, living and working throughout Japan," a statement released to Eurogamer reads.
"We are very conscious of the parallels between these events and the underlying theme in MotorStorm and are doing everything we can to be as sensitive as possible to the situation.
"Although the game itself is already in distribution, we are ceasing any further shipments and removing as much of the marketing materials as possible."
It will be released in the UK eventually, just... not now. This is one hell of a last-minute delay; I got a copy of the game from SCEE earlier this week, and boxes full of them were already in the pipes on their way to retail shelves.
UK MotorStorm Apocalypse delayed [Eurogamer]