"We've looked into doing something similar for Dirt 3 but it's not technically possible," a Codemasters rep told Eurogamer. "It's hard-coded into the game." Removing the VIP pass requirement would involve a patch, the publisher explained, which would likely take longer to push through than it will take for the Store to come back online.
An alternate solution to this problem (though not for Dirt 3, since it's already out) would be to cut out Online Pass schemes in general. We wonder if anyone has suggested that.