An easy change would be to paint the wood white to brighten it up, frost the glass to help obscure the cabinet contents, replace the counter top and hang art on the blank, living room side.

Depends on your lifestyle. But, you could remove the upper cabinets and put a couple pendant lights for openness and light. If space, you could make a bar counter on the LR side.

For the open cabinet side, I'd consider one of these options: 1) paint inside the cabinet back and the shelves a lighter color, or color to go with the dining room 2) attach patterned fabric to go with your dining room to the back of the cabinets--stick on velcro is your friend! 3) find some interesting handmade paper--usually available at an art supply store--attach to the back with double stick tape. Most of these papers are created in widths and lengths that would fit into the cabinets with minor cutting. Do an edited, artful arrangement of storage pieces (not everything that is a set has to go together). If there is a plate rail groove close to the back on the shelves, use that. Often large, fairly flat platters will fit in the plate rail groove, and give you a bigger backdrop. Set up a tray with pretty glasses or decanters on the counter. On the blank side, I'd hang art on the plain upper, with maybe a bookcase underneath.

If this is useless for you then remove the whole cabinet.Decorate this place with lights and some other stuff liye side table etc. And you can also remove uper part of this cabinet and place marble shelf on its lower part and place some chairs.It looks perfect.

I'm thinking they are functional. Probably not the only "dated" thing in the house. Work with some paint and something for the backside.