As SharePoint 2010 is released as RTM since few days, there is already an issue with the user profile synchronization service.
When you try to start this service to enable and manage user profile synchronization, the service will stay in ‘starting’ mode for a while. This ALREADY a known issue on SP 2010 – according to few information from ex-colleagues at Microsoft.
The service will stay in starting mode for while but should change to started after more than the ‘10 minutes’ as TechNet said (it’s more about 1/2 day).
This doesn’t block any other configuration or use of SP 2010.
We may hope to have something to solve this quickly.