Foucault’s major works – his sole-authored books, plus some articles – will appear in a two-volume collection in 2015 as a prestigious Pléiade edition. Thanks to Colin Gordon for alerting me to the news. Frédéric Gros is interviewed about this here (in French). Among other things the interview says that the final Collège de France course, Théories et institutions pénales (1971-1972), is due out in 2015, and that, in common with other volumes, the Pléiade volumes will be a critical edition.
Foucault News 