The Silverlight proces designer in K2 keeps surprising me every time I look at. Recently at the SPSaturday in Melbourne I saw the latest update and it was good.
The new feature grabbed my attention was the control IT will now have from a Governance perspective on workflows. With this designer, SharePoint admins can specify who has access to it, what they can use within the desinger and the designed process has to be approved before it is published for production use.
All of this is configured from within the SharePoint UI. Fantastic!
Read more about this from the K2 team here