To simplify the construction for you, it is a very long halter dress.
The straps are draped and brought to the front waistline. Since those don't hold up the dress, there is a second practical set of straps under the draped set. (the two sets of straps seen here http://www.exposay.com/celebrity-photos/rihanna-madonna-and-gucci-host-a-night-to-benefit-raising-malawi-and-unicef-arrivals-04fyvM.jpg
) The skirt has a slightly gathered front. If you look up "ruching" or "ruffling" it is fairly easy to apply.
I would have made it in these pieces:
1 front-gathered skirt piece
1 front breast-piece with two gathered straps
2 practical straps to keep the dress in place
I think you can do this if you just take a whack at it. It will take up a lot of fabric though (I reccommend a cotton jersey). Try practicing with pins, then when you get a drape perfect, you can sew it in. PS be careful if you're not used to sewing slinky fabrics.