We've got experimental pgRouting windows binaries available for windows PostgreSQL 9.2 32-bit and 64-bit for pgRouting 1.0.7 development branch. More details on our Boston GIS blog page.
The final versions we plan to release with upcoming PostGIS 2.1 PostgreSQL 9.2 on stackbuilder as part of the PostGIS install. Barring no difficulties we'll also have experimental binaries for PostgreSQL 9.3 releases once 9.3 reaches beta.
This version and upcoming pgRouting versions support the PostgreSQL extension model, so if you have postgis already installed, its just an additonal simple step:
CREATE EXTENSION pgrouting;