The 2008 Malibu is already available...pricing would be on the Chevy website. From what I understand there are only very minor changes to the 2009 model. I guess the biggie would be a new 6 speed automatic transmission for the I4...which might already be available in the late 2008 models.
Any particular reason for specifically chasing the 2009 over the 2008 (since they are the same design). If you're looking for the mostly minor (except the new transmission) changes maybe its worth a trip to a dealership and see when those modifications might start appearing - assuming the dealer/sales staff are on the ball.