What we are working on right now is coloring and painting. This is a large area with lots of functionality, so this will be spread over a few alpha releases. But it includes “paint layers” suitable for coloring your animation, including fill tool and color picker, but also drawing/painting in color and cool ways of changing/adjusting colors already used in your animation.
At some time after that we plan to have notching tools, so you are able to just push (move) your lines slightly (without any degradation or blurring) which is excellent for close inbetweening etc.
Coming quite soon are features to store your draw tool settings, so you can easily make a set of favourite pencils, markers and brushes and quickly get to them.
As for a real photoshop-like brush system, we plan to look into that as the first thing for the next major future release.
Did you have any specific hopes/wishes? Ideas are very welcome!