Julie -- You have several options and getting feedback here is a great first step.
As you know, now is not a great time to sell, but since there's a good deal of equity in the home, you should be able to easily get more than is owed on it and split the proceeds with your brother.
On the other hand, if your brother and you wouldn't mind taking on the duties of being a landlord, renting the house out might be an option. This way you should be able to cover the montly mortgage payment and continue to build equity in the home while you wait for the market to improve. If you decide to take this action, however, be prepared to rent it out for some time as it will likely be some time before home prices actually start to increase, even if the market does start stabilizing some time soon. Being a landlord isn't always convenient, but it might be a good way for your brother and you to build more of a nest egg for retirement with only modest effort.
If either of you needs a place to live, of course, you may want to consider moving into the house, but that complicates how you would split any proceeds for the house.
Before you do anything else, I think it would be worth the investment to talk with a good tax professional who specializes in real estate law in KY to help determine which of these scenarios would best fit your needs. You'd hate to make a decision in haste only to find out that you could have saved a great deal in taxes if you'd taken another course of action. Good luck!