It's a little disappointing to see that the President's economic stimulus act adds computer expenses to the list of 529-eligible expenses for the years 2009 and 2010 only. To many people, including me, the explicit inclusion of computer expenses was needed to correct an oversight, and not so much to stimulate the economy. In fact, if Congress had failed to amend the law, there was a pretty good chance the IRS would have created a new regulation to allow 529 distributions to pay for a college student's computer.
By making a statutory change, but restricting it to 2009 and 2010, you can bet that IRS will not allow you to count the cost of a computer in your bucket of 529 expenses after 2010, unless the college explicitly requires its students to come to school with their own computer.
What's interesting is there seems to be a loophole of sorts in the new provision regarding computers. Although you must pay or incur the cost in 2009 or 2010, nothing requires that your beneficiary be in college during these two years. The costs will count if the computer technology and equipment are "to be used by the beneficiary and the beneficiary's family during any of the years the beneficiary is enrolled at an eligible educational institution."
In other words, if your child won't be going to college for another five years, but you use 529 money to pay for his or her laptop now, it appears to me (will the IRS agree?) the 529 distribution qualifies as tax-free provided the laptop will last long enough to be used in college. I suppose that is a stimulus after all.