I have just upgraded several of our users to Office 2010 from Office 2007. There are a few who are having trouble with Outlook. They can't send or receive email from their desktops. It still works in OWA. I can send them an email and OWA will receive it, but Outlook will not. Also when they close out of Outlook they get an error message that says: This file is in use by another application or user.(NormalEmail.dotm)
then it asks if you want to save it. I normally hit yes because that gets rid of the message faster.