I was skimming through some recent ACM proceedings, and an article caught my eye.
It’s not massively parallel, but it has the central idea of a dynamic dependency graph (allowing dependencies to be added while building) instead of static dependencies a la make.
This is a video of an older version: http://vimeo.com/15465133
The Haskell package is here: http://hackage.haskell.org/package/shake
It’s notable for the brevity of its notation.