Price is a no-go for me at first few gens, I just can't spend that much on a phone. Ignoring that and just talking about the product itself, durability and the crease are my only issues. To be honest, I actually would consider one of these if there was a strong carrier deal and it was durable, even if I don't really use the inner screen as much as some others. Based on the mockups I am seeing, the aspect ratio of the outer screen is intriguing. I have always favored a more square ratio on almost everything I use, the phone is no different. Give me a bigger keyboard and less cramped feeling images when I zoom in on them. I will absolutely try to test thing out in a store and see how it feels.
I would only fold it open to inspect documents, that's about it. But that is still a very nice use case for the larger screen, and it would probably make me use my phone more than I currently do, even at home. Maybe even extended typing would become considerably easier. These are worthwhile advancements.