Official Activision blogger Dan Amrich has confirmed that Blur's multiplayer beta will start next week, on Monday 8th March.
"Several websites will be launching contests and giving away beta tokens starting on Tuesday, 2nd March," he said. "The gameplay sessions that those tokens unlock do not begin until Monday, 8th March."
News broke (along with some erroneous reports that the testing would being today) when subscribers to the Fileplanet website were invited to "exclusive access into a highly classified Xbox 360 beta event". Respondents said the game was Blur, according to Kotaku.
Activision exec Mike Griffith announced a March beta for the Bizarre Creations racer earlier last month. So far, Xbox 360 is the only format that's been mentioned in connection with the test.
Blur is due in the second quarter of this year, some time between the start of April and the end of June. We took a trip up to Bizarre's Liverpool office to see it recently, so watch out for a report soon.