The PlayStation 3, like it's more-popular competitor the Xbox 360, is a power-hungry console. The existing systems can consume more than 200W while in use, putting it nearly on par with a low end desktop computer. While the PS3 has not suffered from the numerous heat-related issues that the 360 has, it was still an area Sony sought to improve in.
According to recent reports, newer versions of the PS3 are tackling that. They are supposedly using a 65nm version of the Cell processor, cutting the power draw of the unit all the way down to 135W - a much more reasonable amount for a device that squats underneath your TV. This is an obvious step up, with the Cell moving to a 65nm process earlier in the year and Microsoft making a big deal about their move to 65nm. Where it might most benefit Sony, however, is if they can eventually pass the cost reduction from a smaller CPU onto their potential customers, many of whom are still put off by the steep price tag of the ailing console.
As the 40GB version of the PS3 was intended to lower costs anyway, hopefully they will run with it.