As part of configuring the web part, you need to copy two encryption keys from the Operations Manager Web console into SharePoint. In earlier testing, with beta and release candidate software, this worked flawlessly. In our testing with RTM software we ran into a weird intermittent error where the dashboard could not be accessed by using the shared credentials.
In the web part the following message is displayed:
An unexpected error has occurred.
If you click the link to show error details, you see the following:
Microsoft.EnterpriseManagement.Presentation.Security.ConnectionSessionException: Unable to create connection session.
Imagine my concern when using the detailed error message resulted in zero results on Google. So, we tried a whole bunch of things, but what fixed it was uninstalling the Operations Manager Web console and reinstalling it. This regenerates the encryption keys in the Operations Manager Web console that are used for connectivity from SharePoint. After SharePoint was updated with the new encryption keys it worked without any issues.
I did verify that the shared credentials were being passed properly to the Operations Manager Web console. You can see this in the log for the Operations Manager Web console web site. No errors were displayed in that log. So, it must have been something at the .NET level which is a bit outside my area of expertise.
Ultimately, I don't know whether the encryption keys were the problem or the Operations Manager Web console was the problem. Uninstalling and reinstalling the Operations Manager Web console could have fixed either one.
Detailed steps for configuring the Operations Manager Web Part and shared credentials are here: