Getty's blog post about it: http://blogs.getty.edu/iris/open-content-an-idea-whose-time-...
An example page where you can download a 4264px × 3282px copy of Van Gogh's 'Irises' (28mb .jpg): http://search.getty.edu/museum/records/musobject?objectid=94...
I'm wondering how long it will be before someone creates a .torrent with the entire collection...