BTW, I don't like promoting Linode competitors on Linode forum, but there's one with "files (in the) cloud" service that I used for over a year, primarily as offsite backup. With a flip of a switch you can turn the bucket into public CDN, and it has nice Python bindings so I incorporated it into my apps directly, deliverying all uploaded content to it.
The drawback was (still is if I'm not mistaken) that you can't CNAME the buckets so if you want to switch the provider it'll be a huge pain to rewrite all the links to CDN'ed content.
So if Linode was to implement one, I'd say these would be awesome features:
1. RESTful api, with Python bindings (

)
2. Ability to select locations
3. Private/public bucket switch
4. CNAME'd or otherwise branded bucket URLs
5. Automatically scallable, ie. or at least storage upgrades with a flip of a switch