The Bad News...
The business of real estate has changed significantly over the last year. Homes for sale stay on the market longer, and interest rates have risen slightly, which for many people, changes the amount of house that they can afford.
The Good News...
For Sellers: The market is showing signs of recovery - especially in the DC Metro Area. The length of time properties remain on the market has decreased 10% on average, and attendance at open houses is also up.
The services of a dedicated real estate professional will certainly pay off in this market. According to (some source), most people who engage a realtor sell their homes for 16% more on average? 
For Buyers: There are still great deals to be had. The Federal Reserve Board has declined to raise interest rates the last 4 times that they have met. In short, there is an opportunity right now to snap up the home of your dreams for less than you expect. But you'll need the services of a Realtor to find those great deals, and to ensure you don't pay more than fair market value.