My first thought: great - we can retire our in-house multi-part uploader (EvaporateJS) [0] and use AWS's. But digging into the API, it seems like most of the real work of multipart uploading (managing part failures) is not done by the SDK [1], so we'll stick with EvaporateJS. It's working pretty well for us. We've seen 22GB uploads go through (direct from browser to S3). The main issue that we know of [2] should be fairly easy to fix if anyone wants to contribute!

[0] https://github.com/TTLabs/EvaporateJS [1] http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/frames.ht... [2] https://github.com/TTLabs/EvaporateJS/issues/6