Hey Javier -
Yes, you should see an updated add-in which handles the changes in PowerPivot 2012 very, very soon. No, can't tell you exactly when, but soon... Hope this helps?
It does. I have another question regarding the connectivity with the current PowerPivot though. One of the functionalities that currently exist in PowerPivot for SharePoint is cache management. When a PowerPivot is published, sharepoint creates a 'cube' like model in SSAS. If the same PowerPivot is republished with changes, another 'cube' is generated but the old one is still there in case existing clients are still connected to that version of the file. In other clients (SSRS, Excel), when connecting through a URL, the most current version of the 'cube' is delivered. In Tableau, the view gets cleared out and the connection is broken, which is not ideal.
Are there any plans to fix this or is there a workaround? The issue must stem out the fact Tableau is generating MDX which includes the specific GUID version of the PowerPivot 'cube' when autogenerating queries.
I suspect you're correct - the GUID after the "sandbox" name essentially is changing each time the cube is refreshed?
You may want to report this to firstname.lastname@example.org so they can open up a bug/feature request to ask for this improvement.
I will. Thanks Christopher