There is a good article about the security of our power grid. Unlike the innumerable fear-mongering writeups I generally find, this one is quite reasonable.
In particular I find this paragraph about the increasing proliferation of "smart-grids" interesting:
While Meyerrose, Mansoor and other experts agree that the utility industry's vulnerability will grow as its command-and-control systems rely ever more on computer networks, those concerns are not new. Some security experts have cautioned against the growing use of "smart grid" technology — which relies even more on computer networks to allow both utilities and individual consumers to monitor and reduce power usage. There are already 2 million smart meters in use in the U.S., and the Obama Administration's 2010 budget includes $4.5 billion in spending on such technology. The fear is that these meters may allow hackers access to the grid's control systems. But smart-grid backers say the opposite is true: the use of more-sophisticated monitoring systems makes the grid safer.
Of course, they will say this because that is good for their business. The truth is that it depends on the details. If these systems are designed with security in mind they will be safer. If not (and this is more likely), the new smart grid will be less secure than the "dumb" grid we have today.