Unfortunately when creating a Web Application, SharePoint 2010 uses the SharePoint only property Display Name for the STS application
Microsoft overhauled the Profile Service in SP2010. To get them to work, in the public beta, is tricky, but now there is a useful guide
The activity feed in SharePoint 2010 is very interesting. It is a way to see and read what your co-workers are doing. Most of your actions in SP2010 will end up in the activity feed. But what about your actions and updates outside the organisation? For instance your twitter account?