Full disclosure. I'm one of the Umano cofounders, I figured it's time to jump in here.
There are many things mentioned in comments that I'm not going to try to cover, but I will cover the basics. I'd be happy to answer any direct questions.
The vision behind Umano is simple. We want to provide our users with a new way of consuming content. Many times it's the content they wouldn't otherwise read. How many times have you come across an interesting article that bubbled up in your twitter stream, you added it to your Pocket, and you forgot about it forever and ever. Reading is a heavy task. Reading takes time and your full attention. You can't read while you are cooking breakfast, getting dressed, standing in a crammed Muni bus, or riding on your bike to work. Listening is passive. Listening is easy. Listening allows you consume longer pieces of content with less effort, while doing something else. Umano is here to offer great content in a different medium.
We started Umano with no licensing deals from any publishers (big or small). Sure, having licensing deals would be amazing, but "Even if 100% of people they asked were fine with it (Scott seems to imply he is) probably less than 10% would bother to respond, that then knackers their startup instantly." as @robinwarren said above. Now that we are bigger and more mature, we have deals with many large publishers. However, at this point it wouldn't be scalable for us to ask for permission from all bloggers that write amazing content that our community would like to be voiced. If the content producer doesn't want their content on the platform, we will happily take it down. As we grow and start to make money, our mission is to do revenue shares with content owners. Until then, the benefit that we bring to many bloggers is distribution. Popular articles often generate a significant number of listeners. Finally, one interesting point about Scott's article that was narrated - it was actually requested by one of our users through a new "Submit Any Link" feature that we recently launched as an experiment on Android.
Now to attribution. We never claim that the content we voice is original Umano content, and we always provide attribution. We link to the original article, and always include the name of the publisher and the author in the narration. Scott mentioned that we do it poorly on mobile web and will fix that shortly.