From the site: Everything in the hacks section is provided as-is unless you specifically have a contract with smugmug. They're not supported, endorsed, or guaranteed in any way. We'd love to fully support the API and other goodies with smugmug's AAA customer service, but we're just not there yet. Soon, we hope." Note they also offer a WebDAV interface for upload, as https://upload.smugmug.com/smugdav.mg.
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Thanks for the most excellent mashups guys, thrilled to see a great company like smugmug prospering and really servicing the photo sharing community.