I would say that the mantle could be updated but I am not 100% sold on painting the brick. Can you supply another picture of the whole room so I can get a better idea? Are you set on your wall color currently?

Do you use your fireplace? Always concerned about soot marks when people paint their fireplaces white, or whatever solid color. We use ours lots. Personally, I like the red brick tones. Have you considered painting the walls instead? Perhaps a dark red on the fireplace wall only as an accent?

Yes I just painted the room last fall so repainting would not be in our favor.

Yes we use the fireplace all the time. We just painted the walls last fall so we would like to keep this color.

If you are trying to brighten the room I would consider art and some white objects on the mantle as opposed to painting. I would also consider removing the curtains. It doesn't seem like you need them for Privacy given the short rods? The brick looks nice I would try other things before painting.
This photo is just to show something brighter with some white accents - I know the style is different from yours.
http://houzz.com/photos/1965849

The mantle shelf looks too high, should be lower if possible. I'm all for painting the brick, but it's a personal choice.

Here are some pictures to help you:

I have a similar fireplace and I really like the natural brick. Have kept it even though the trend now seems to painting brick. My wall is painted a dark color and it really makes the brick come alive. I know you have just painted so that is probably not an option. But if you were planning to paint anyway (the brick) perhaps you could consider just painting the fireplace wall. I used a dark green on my wall, a charcoal would also look nice. I also, agree that removing the drapes from your sliding door will help to lighten the space. Your floors are beautiful.

I like the brick and would keep as is.