It depends upon your goals and how much you owe on the property. If it is an investment(rental-which is tied to your monthly mortgage payment+Condo fees), and/or if you can hold the property and still achieve you next housing goal, then you should hold, because the metro is coming.
On the other hand, if your goal is to buy your next home and you need proceeds from the condo to do so, than this is a very good time to sell, and buy the next one. You will enjoy the Reston market in recovery (list at the end of February), plus enjoy the benefit of low interest rates on your next mortgage, and if you buy "up", a nicer condo in the Town Center, or a townhome, or a single family, these assets should appreciate in value at a more rapid pace than Edgewater.
Also, if you have young children or are planning to start a family and need to use a public school system, you may want to compare the schools in order to make your decision.
Feel free to come in and meet with me anytime :) and good luck!
Helen Manning, Realtor