The PostGIS 2.2.0 bundles for windows for PostgreSQL 9.3-9.4 (both 32/64-bit) and PostgreSQL 9.5beta1 64-bit are now on stackbuilder. I'm working out some compile issues for the PostgreSQL 9.5beta1 32-bit so don't have those ready yet. This includes pgRouting 2.1.0 and inaugural release of PostGIS SFCGAL extension, OGR FDW spatial foreign data wrapper, and pgPointCloud on windows.
I have also updated our popular BostonGIS - Part 1: Getting Started With PostGIS: An almost Idiot's Guide to utilize PostgreSQL 9.5beta1 and PostGIS 2.2. Still on our todo is to update the loader/query example and also the pgRouting tutorial for pgRouting 2.1.0. A ton has changed in pgRouting 2.1.0, so be sure to buy our book pgRouting: A Practical Guide which will have a preview release sale coming soon with first 4-5 draft chapters available and all on final publication all chapters (approximately 10-12).
Check out the PostGIS Bundle 2.2 extensions higlighted in yellow in pgAdmin extensions drop down
To take full advantage of what PostGIS 2.2 has to offer (notable true KNN distance for geometry, geography, and 3D geometries -- not just bounding box like is available for PostgreSQL 9.4 and below), you need to use PostgreSQL 9.5. So start testing out your apps on PostgreSQL 9.5 now so you will be ready when it hits release.