PC makers aren't jumping on the SP1 bandwagon just yet, mainly because SP1 is more a collection of bug fixes and security patches than anything that adds sexy new features or functionality. SP1 isn't problem-free either, and there's already a list of problems associated with the update.
Despite the need for a service pack to address security issues and bugs, manufacturers are apparently very happy with the reduction in service calls they've seen with the new OS.
A number of factors apparently affected PC makers' slow approach to the service pack. Many manufacturers have reported a dramatic decline in technical support calls with Windows XP compared with older versions of the operating system.XP is a huge improvement over the Windows 9x series that used to plague home PCs, so that probably has a lot to do with the drop in service calls. A more computer-savvy population can't hurt, either.