Just because it was looking better indoors a week ago doesn't mean that it wasn't already dieing. Sometimes, once a plant starts showing signs of decline, it's too late. This happens a lot with pre-packaged "bonsai", especially Junipers. Moving it outside, which is good advice in general, isn't necessarily going to save a dieing plant.
Have you dunked the whole base yet, as Oliver suggested? The peat/soil looks totally dried out to me. It probably needs to soak if it is to absorb water.
If it does die, I would suggest that you use this as a learning opportunity. Maybe bonsai isn't for you. Or maybe, like all of us, you're going to kill a few plants as you work towards figuring out the most important part of the hobby/art - keeping trees in pots alive.
Watering a sickly bonsai is even trickier. A tree that is struggling isn't going to use alot of water since its roots are compromised and incapable of drawing much up. A really sick plant may only need watering every three or four days. A recovering plant with a more active root system may require watering every day, though.
