Photos courtesy of Simone Eich
And the nice thing is that after making the first shawl, you have enough yarn left to make its twin by changing main color to contrasting color and vice versa.
Want to knit a fingering weight version? I'd just choose two fingering weight colors and go down one needle size. You'd have a slightly smaller shawl and many more color options. You could use Lang's Jawoll Degrade, fingering weight Zauberball or Zauberball 100, or Sausalito (we just got in all the awesome new colors).
Of course you could also choose a striping yarn and then a contrasting solid, kind of like Heather used in her Prism shawl.