I'm not sure how much DST really helps with energy savings. The lighting load in most homes is a very small part of the electric bill, especially with compact fluorescent lamps and other energy efficient lighting technologies out there these days. Most homeowners are pretty responsive to these technologies and readily use them. Most homeowners too are very good about turning off lights when they are not using them too.
As far as commercial ventures go, well, most office buildings are lit up just as much by day as they are at night, because modern buildings usually don't have any windows or other access to natural lighting. The lighting load of a commercial building is quite significant not only because of the simple fact that the presence of natural light has no effect on them, but also because businesses require much more ambient lighting than a typical home needs.
Most business really don't care about saving electricity anyways! Once can drive up the "main drag" of any typical town well after business hours and see the parking lots of closed businesses lit up like movie scenes. Don't ask me why they do this, but a single suburban parking lot consumes THOUSANDS of watts of electrical power. Imagine leaving your dryer and your electric water heater running continuously all night long! Just simply throwing the switch once everyone leaves is all that's needed, what's so hard about that! Daylight savings time IMHO does not save a single watt becaue of this irresponsibility. Extending DST was just one of those little political things that President Bush dreamed up to make people think he is interested in reducing energy consumption.
What's even worse is the broken timer syndrome that is all too common. The light timer or optical sensor breaks, so the business just leaves the lights on 24-7. It's just as bad as watering the lawn during a rainstorm, which is also an all too common waste!
Still, I wish DST was used all year! I'd rather be getting up in the dark, rather than driving home in the dark
