Amidst minimal appetite for Windows security, what of Longhorn?

Silicon.com's Dan Ilett has a news brief that quotes Mario Juarez, product manager of security at Microsoft, as saying "We know that the percentage of people using Windows XP SP 2 is lower than we would like it to be....One in three machines that run Windows XP is running SP 2. Customers are still reluctant to upgrade."  So, here's a good question:  If, after almost a year of being available,  nearly 66 percent of XP users aren't willing to get an upgrade to Windows that's free - one that's supposed to make their OS 15 times safer than it was before --  how on earth does Microsoft expect the larger population of Windows users (many of whom are running a version of Windows that's older than XP) to get interested in Longhorn (the codename of the next version of Windows)?