With the activation changes of XP SP3 will users need new product keys?
No. XP SP3 can be deployed on top of XP SP1 and XP SP2 with absolutely no issues. Users will not be required to enter, or re-enter their product key, or to re-activate the operating system. Furthermore, when performing a clean install of the XP SP3, users will have the possibility to deploy the operating system without entering a product key during installation. But they will have to deliver a product key by the end of the 30-day Initial Grace period and activate XP SP3.