IDC has released a new study, analyizing the optical storage market for 2005-2007 and providing a forcast for 2008-2012. According to their findings, Blu-ray adoption will gain momentum 2009. However, DVD burners will continue to dominate the market until 2012.
Overall PC market growth, driven by portable PCs, will give the worldwide CD/DVD market a moderately positive outlook in 2008 and lead to increased demand for slim drives. Despite the ramp of Blu-ray drives, DVD burners will continue to be the leading volume product until 2012. However, as the PC market's adoption of DVD burners becomes saturated and increasingly commoditized, Blu-ray adoption will accelerate in 2009 and Blu-ray drives will become the majority of the total market value in 2012.

"DVD burners will remain the bread-and-butter business for ODD vendors," said Wolfgang Schlichting, research director, Removable Storage at IDC. "Despite Blu-ray's win over HDD in the format war, Blu-ray drive adoption will be limited in 2008 because of their high price and only moderate consumer interest."
If you'd like to read more, the IDC's entire press release can be found here.