A: When a service pack for an OS is released, the Microsoft product teams goes through a testing and validation process for their products. Once they're done, they release a support statement, at which point you can deploy the service pack to those systems. Typically this process takes between 30 and 90 days once the service pack has been released, depending on the product.
You should hold off deploying the new service pack to any system until you confirm that the service pack has been tested with the products that run on the OS, to make sure the service pack doesn't cause any problems. This statement is true for any software, not just Microsoft products—although their timelines to support a service pack may not fall into the 30-90 day timeline.