This was one of my favorite finds over the weekend and it's not surprising that it's become a favorite for a mass of other bloggers ;-) It's called the "Tube Top Dress" and the package comes in 2 different colors + 2 different lengths. The bodice area is a sculpted prim and it works seamlessly with the rest of the outfit.
Xelyn is wearing: Tube Top - Dress Parade by Fishy Strawberry (L$60 @ The Dressing Room)
Shoes - Grim Bros. Vie en Rose