If other publishers have signed up, yes, it would be wise to show a few. It would get some people more excited about trying their app, when/if it does come out.
They can still PR the publishers when/if the app is ready. Hopefully they would have more publishers signed on.
Given that REDG didn't show how the app works, it's a moot point to other publishers. I don't know how you are impressed with still shots. It isn't like we saw how much the image was magnified. A very short video would have illustrated the points much better than the still pictures and text.
I'm not sure how awesome streaming is. With the Marvel app, my tendency was to download entire book to read, discard, then download new books. The books were available offline and not dependent on my internet access.
I can see being free as the selling point, but, I think content is the bigger selling point. REDG hasn't shown any must read content, and no indication they will have access to any.
