I often enjoy the cynicism of HN as a counterpoint to the typical breathless media coverage of new technology. However that now famous comment on dropbox is a good demonstration that cynicism isn't a short cut to truth.
I'm not saying it won't work (I have no idea - there's no reason someone can't replicate all of s3's features eventually). I'm just saying that this "we're going to replace run s3 out of business" optimism is pretty unfounded right now. And on a factual level, "featureset is quickly approaching Amazon S3" is pure bullshit.