CRM 2011 Update Rollup 8, not to be confused with the upcoming Service Update 8, is now available for download. This update addresses a number of Outlook client synchronization issues, a performance fix when switching folders in WAN and more.
Remember, Update Rollup 6 is a requirement for UR 8 so ensure your systems have UR 6 before attempting to apply UR 8. You will be able to uninstall UR 8 if needed but you will not be able to uninstall UR 6.
I would recommend checking out Donna Edward’s Blog for more of the details. She has a great blog with a ton of information.