When I asked, United Front Games was quiet on when the beta for its upcoming ModNation Racers would begin. I had my suspicions it would begin before year's end, and I was correct!
Sony has sent out emails confirming that the beta for United Front's racer/creators dreams will begin this month. While those who purchased LittleBigPlanet: Game of the Year Edition should already have a code (it came in the box), everyone else can sign up online for a chance to participate. Alternately, you can either be an existing subscriber to Qore, or subscribe on or before December 15 to receive a voucher.
When I visited United Front a few weeks back, I had a chance to check out what the beta will look like: a complete and total time sink. I say that in a good way -- with at least two pre-made tracks, thousands of parts to create a character with, and the full-featured track editor, there should be plenty to explore before the game launches next year.