I would really like to see improvements in the way pen weights are connected to colors. Namely that a pen weight connected to a color can be made to override any other pen weight assignments, even within groups and symbols. It is very frustrating trying to get symbols to print properly (short of exploding them and re-assigning colors and pen weights).
Similarly, i would like the pen weights to be assigned to objects that have a color assigned to them by layer. For instance when i make a layer color "185" and i have a pen weight assigned to that color, objects on that layer that are assigned a color "by layer" should also have the pen weight associated to them.
Lastly, i would like to have the ability to have multiple profiles saved for pen weights connected to colors. If some of the issues with applying pen weights connected to colors can be worked out, it would be nice to have several profiles to automatically assign proper pen weights depending on the scale of the drawing or even the printer it is being sent to. That is, i want to be able to select a pen weight color profile and have the pen weights assigned to the colors without having to go back through the drawing and manually make the changes.