Having already added every type of Essbase grid available (MDX, report scripts, ad-hoc, free form), the next grid type was obvious:
For now relational grids are read-only, but I'm planning to make them writable in the near future. Currently two "Database Types" are supported: Microsoft SQL Server and Oracle, since these are the most widely-used in an enterprise environment. The next to be added will likely be MySQL and PostgreSQL, providing coverage for the 4 most popular database engines.
Sharing relational grids is the same as other grids. Clicking on the "Database:" button also displays the standard grid slide-in panel:
Once relational grids have the same functionality as Essbase grids, I'll begin integrating the two types. First, I envision composite grids that can contain both relational and multidimensional sources. I, myself, have several use cases for this - specifically, drilling down from consolidated Essbase data to source data in a relational database.
You can download cubeSavvy at the usual place.