My husband and his brother will inherit their Mom's home, still in her name, when she dies. They both have power of Attorney now. She is not going to live long I'm afraid. So we want to sell her house, she lives in a private adult care home, which my husband has taken a line of credit against her home to pay for her care. Medicare does not pick up any of that care. After reading about taxes in 2010, I'm concerned about them for 2011. My husband and his mom live in WA state and his brother lives in VA.

You can see the yearly exclusion and rate chart on wikipedia under 'estate taxes US.'
Note that 2010 rates were repealed in Dec 2010.
You can look up each state tax (if any) on the state.gov sites.
If you put the house up for sale now and she dies before the closing, it will be delayed because of probate, and buyers might be reluctant to take the risk (and they have a right to know).