In Microsoft Dynamics CRM 4.0, you cannot add Leads or Contacts to Marketing Lists automatically using workflow. This still doesn't seem to be a possibility based on what we see in the beta of Microsoft Dynamics CRM 2011. However, since Marketing Lists in 2011 can be either static or dynamic, it is much easier to create a solution where individuals show up on marketing lists because of an action initiated by workflow.
In the example below, I've created an Interests list on the Contact record to indicate all the various things this contact might be interested in.
I've also created a dynamic Marketing List with a Type of Dynamic.
In that case, when I go to Manage Members, I specify the query I want to use. The only way an individual can be added to a dynamic marketing list is if they match the query criteria.
From there, I can create a workflow process that adds an interest to a Contact and that in turn adds the contact to the marketing list. This might be triggered manually, or it might be triggered based on a Dialog or response to a Campaign.
Multi-step campaigns are currently not fully automated in Microsoft Dynamics CRM 2011--meaning you cannot have a series of Emails sent out automatically on a scheduled basis. However, with some planning, you can have the marketing list created automatically; so all you have to do is click "go" to send out a scheduled marketing touch.
Please let us know if you help from the Microsoft Dynamics CRM experts at PowerObjects.