There is no longer any need to register for the the beta program so this video has been disabled. When you register for SAP StreamWork then you automatically have access to the process modeler because the tool has now been released to be GA.
This video shows how to get your access to the new process flow tool in SAP StreamWork which is in beta release as part of the gravity project.
There’s a Sketching the process to making a good decision- and then executing on it. (and what the tool enables) and another blog describing it’s The specified item was not found.
And please by all means invite a colleague (or more) to join, because it is much, much, much more fun and valuable evaluating this with a colleague at the same time. If you’re on your own, it’s only as much fun as writing e-mails compared with using a chat program with friends 😉