I and Alberto started a collaboration with Rafal Lukawiecki and we will publish video tutorial on the Project Botticelli web site.
The first video is already available: DAX in Action shows you how the power of DAX in PowerPivot solving a common pattern (counting the new and returning customers) that is not so easy and fast if implemented in other languages like SQL or MDX. We will publish other videos in the coming months and I’d like to get feedback about the structure and the content of what you can see now, so that we will be able to improve the content in future recordings!