The ProgressiveMigration project in the downloads does not build. The build process gets two fatal errors compiling the mapping model “v1_to_v2.xcmappingmodel”. I’m using the latest versions of Xcode (3.2.2).
(It appears that v2.xcdatamodel is actually a duplicate of v3.xcdatamodel. I’ll try grabbing v2.xcdatamodel from another project and report on my results.)