By 2009, most new laptops will use solid state drives This will reduce power usage by up to ten times from what the hard drive would have used. A 20% reduction in overall power usage.
There are bigger impacts from faster boot and restart times Plus database and application performance is better from applications that would have had a lot of paging from the hard drive.
A totally remade laptop and handheld devices with lower power usage would need a new monitor such as OLED version, and redesigned CPUs and wifi components.
OLED and advanced LED can get to 30 lumens/watt or about double the current standard, but very advanced versions can reach 200 lumens/watt or better
Cameras can be made 50-100 times more efficient