Split field entity into two: data field and visual field

(sorry for my english)

I'd like to offer to split field entity into two: "data field" and "visual field".
Drawing an analogy with CCK: "data field" is "field" and "visual field" is something like "field formatter".
Each visual field can have options and parameters. Options set by form provided by visual field handler (like in field handler at this moment).
Parameters is a list of parameters that can be set either to "data field" (mapping data field onto visual fields) or to user values.
This will also give users the ability to specify and customize field appearence directly from view.
This will eliminate "Exclude from display" option from base field handler.
I think that this solution is more logically correct and add additional capabilities described above.