Last week, I removed my VS2010 beta installation and installed VS2010 RC. The RC is much more stable, and as a bonus renaming a feature in a SP2010 project now works.
We have been building lots of features lately, and I was very pleasantly surprised to see this bug already fixed.

A collegue created a SP2010 workflow in visio, and imported it into SharePoint Designer 2010.
His flow used the following actions: 

• AddListItemPermission
• InheritListItemPermissions
• RemoveListitemPermission
• ReplaceListItemPermissions

SharePoint Designer 2010 throws an error when he validates the workflow (check for errors) or tried to deploy it.

The error (for searchablility):
This workflow action is not supported in this region of the workflow.
It can only be inserted in certain types of blocks.

SharePoint Designer does not show the actions as available.
After a bit of searching we found that these actions can only be added when inserted in an Impersonation Step.
This is logical as the impersonation step runs as the author of the document, in stead of the workflow starter.

Hope this is helpful.

Alexander Ketelaar (www.sharepoint2010.nl) found the following list of known SP2010 beta 2 issues.

http://officebeta.microsoft.com/en-us/sharepoint-server-help/microsoft-office-servers-beta-2-known-issuesreadme-HA101267292.aspx?CTT=1

Thanks to Jeffrey Tummers for retrieving the id's

This tool makes contenttype development a lot easier.

Click the contenttype together in MOSS and copy the xml from this tool into your sharepoint solution.

This tool works with SP2010 beta.

http://www.codeplex.com/MOSS2K7CTypesViewer