We know about the Wheaton one Sunday, but I was not aware of the Arlington one Sunday 12-5.
From The Washington Times:
"This year's Taste of Arlington takes place at 4238 Wilson Blvd., Arlington (beside Ballston Common Mall) and offers grub from 23 ethnically diverse area restaurants. Local band Cityscape provides the tunes, and ABC Channel 7 provides the entertainment via a live local version of "The Bachelor." Admission is free, and ticket books good for 8 tastes are available for $25. 703/841-7768, ext. 333.