The MS08-031 bulletin in particular is rated as a "patch now" requirement, as details on how to exploit some of the vulnerabilities have been published publicly. These updates should be applied promptly to ensure the best levels of protection.
I've currently installed all the updates on approximately 40 Win2000 and XP SP2 & SP3 computers.. Most were done using the Windows Updates site online.. A couple were performed by using the downloaded manual installers from each of the updates. No problems here with any of the updates on any of the machines.