But you bought in a decent area. Prices aren't declining there they way they are in, say, Prince William County. And even though prices may decline through 2008 and 2009, they'll probably then stabilize and then rise.
Relax. You'll be fine.
Real Estate is a long term investment and should be treated as such. If you're here for at least 3, if not 5 years, you should be about even in market value. Longer than that and you should start seeing appreciation again.
if you can afford your condo.
If you can't afford it, you'll need to get lucky for the market to bail you out. A lot of people at the tail end of the bubble (like all bubbles) paid too much because they thought things would keep going up. They found out the truth. Real estate usually goes up. It almost always goes up in value. But it doesn't ALWAYS go up.
Three years down the road you'll have options. You can rent your place out or you can sell it. Most likely you'll do a little better than break even. (Which means that you got the tax savings over the years of residence.) You bought in a great area. I'm sure you'll be fine.