http://www.afterdawn.com/news/archive/4863.cfmAccording to a Japanese A/V news site, Pioneer has demonstrated dual-layer DVD-R burning at the CES expo in Las Vegas, using the existing single-layer DVDR drive, Pioneer A06.
According to the article, Pioneer used only a modified firmware to achieve the dual-layer burning with no needs to modify the hardware itself at all. But only time will tell whether the company actually decides that it is such a great idea to allow consumers to upgrade their drives to dual-layer by simply switching the firmware and not buying a new drive..