I can understand wanting a lighter, brighter feel to the room. However, I get the impression you're not really interested in changing the basic style of the room from it's old timey, country look to something else. So......I would suggest some wainscotting on the lower half of the walls, painted an off white or cream. Then, I would suggest some floor length drapes, possibly in off white. You might check out Country Curtains for inspiration. Then, if your space still isn't light enough, you can remove the wallpaper from the top half of the room. There is another option, however. You might want to consider installing tongue and groove panelling on all the walls, top to bottom, painted off white or cream. That would retain the country look but brighten up the space a great deal. Good luck and repost when you're ready.

Changing the draperies to a lighter material and not tying them back will have a huge impact on lightening the room. Some people paint right over wallpaper if it seems to be on the really tight.Reducing the amount of items on the hutch will also give a lighter feel.You might replace the collage of personal photos with some wall art . I like to match the wall space and shape when I choose wall art. -in your case using one verticle picture about 2 feet long or hang 2 smaller ones one directly over the other to cover roughly the same space.A mirror that reflects the windows will also add light.

I ran into the same problem in my dining room. My wife and I had to steam all of the wall paper to bring it down, what a mess. We then painted with brighter colors. We also added a chair rail to separate upper and lower with different colors. Even white wainscoting would look nice too.