[DataFrame][Request] Multi-dimensional Index

Thanks for adding the DataFrame type! It is briljant, and I have already tried it out, and the current functionality works great.
I have done a small performance comparison, porting some code from a project from Python to C#: having code with row specific operations (the apply() in pandas) I have experienced that in .NET I get 50-100 times faster execution times than with Python+pandas.

To be able to really use DataFrame in our projects, we would need to also have **Multi-dimensional Indexing** capabilities.

It this something on the roadmap, in the nearby future?