As an old HTTP guy I often get nervous about new services. They tend to violate all sorts of key HTTP architecture concepts and just take advantage of the flexibility to do whatever.
I’ve been really happy to see that the Azure Blob storage actually gets this stuff right. They have valid REST semantics with a good URL namespace, support GET and PUT with the right kind of range headers, etag and conditional operation support. They have a smart design for uploading a large blob in multiple pieces (which works around one of the bigger flaws in the older WebDAV support), and all. Anyway, its great to see a team do all their homework and get these details right- I suspect this will really payoff over the long lifespan of a service as it fits in cleanly with rest of the web services world. (note- I’m not saying other competing products aren’t also doing these things right, I haven’t researched those details lately).