Is custom workflow activities supported at all for CRM Online ?
I've found some information saying "yes it is, as long as you use .net 4", and some just saying "no".
Custom Workflow Activities are not supported on CRM Online at this time.
Check out this blog for more details: http://blogs.msdn.com/b/crm/archive/2010/11/05/custom-workflow-actions-in-microsoft-dynamics-crm-2011-online.aspx
Good CRM Links: http://www.workopia.com/Links.htm My CRM Blog: http://microsoft-crm.spaces.live.com