According to DigiTimes, a shortage of blue laser diodes may push back the competition between Blu-ray and HD-DVD until early 2007.
Since manufacturers of blue laser diodes are still unable to improve yield rates, the shortage may result in pushing back the competition between Blu-ray Disc (BD) and HD-DVD optical disc drives in the market to the first quarter of 2007, according to sources at optical disc drive (ODD) manufacturers.

Although several vendors, including Royal Philips Electronics, Hitachi-LG Data Storage (HLDS), Sony, Matsushita Electric, Lite-On IT and BenQ, already announced BD or HD-DVD drives, only Pioneer and Plextor are currently able to maintain actual shipments, according to the sources. Toshiba may soon join them, with volume shipments planned to kick off in September, the sources added.
The article also mentions that Sony has suspended shipments of blue laser diodes to other customers so that they can use them in the PS3. If you'd like to read more, the entire article can be found here.