I have mixed feelings about the return of the Sisters. They are very different than when I started playing them years and years ago. But they have returned with a new two part mini codex in White Dwarf and their online-only line:
SoB Section on GW's Site
On one hand, more armies are always a good thing. On the other, I think these are all old models. They really need the Dark Eldar treatment, especially considering how exquisite the sculpt of Lillith is.
Will I return to my ladies? Well, it depends on the points cost per unit, which will be in the next WD, and whether I can stand this many metal models. Stay tuned.