One of Sony's biggest problems has been supply. Not just with the PS3, but many core components of their hardware business, most especially with Blu-ray devices. In particular, the blue laser diodes they are manufacturing with others have come much slower than expected, resulting higher costs and slower adoption. According to some, that'll start to decline considerably in 2007. Sony will definitely need it if they want to even approach their goal of 6 million PS3's by March, especially since they have not even reached 350,000 sold. Sony's secondary source of the diodes, Nichia, is meeting with very high failure rates. As a result of this, another company is stepping in:

Sharp, in light of the large market potential, announced in November that it is producing blue laser diodes mainly for use in BD PUHs with an initial monthly capacity of 150,000 diodes, the sources pointed out. Sony, in order to attain a goal of selling six million PS3 units globally by March 2006, has to expand its production capacity of blue laser diodes as soon as possible, the sources noted.
Sony is keeping their lips sealed about additional Blu-ray devices, which makes sense considering the difficulty they are having with just the PS3.