Optiarc (the joint optical drive company formed by Sony and NEC) has introduced a "low-price" Blu-ray writer for laptops, the BC-5500A. The drive also supports burning of CDs and dual layer DVDs. While no price was given, Optiarc mentioned that the drive would be aimed at the mid-level laptop market.
Update: The source now confirms that the drive will retail for $335. This is a very competitive price and should result in its inclusion in many future laptop sales.