This questions all this type thing… if you can have different tags-relations (for humans e.g.). The only advantge of types is the possibility to use templates?
Edit. I am really interested in knowing if this is going to happen in the near future. Otherwise I have to rethink my database structure.
Not sure if it was confirmed anywhere, but there is a very high chance that there are plans to implement this.
Keep in mind that grouping is currently not supported outside of the board view.