Neither of those gadgets are going to hit the market any time soon, and they might not get made at all, so if you can't stand the wait then you should check out this new case from PopSlate.
A reader tipped me to a crowdfunding project which launched today on IndieGogo. PopSlate is working to raise $150,000 to finish the design of this case and get it into production.
The case in question is going to be designed for the iPhone 5, and since it uses the Lightning connector it obviously won't be backwards compatible. But anyone with an iPhone 5 will be able to enjoy having a 4" E-ink screen as a secondary display.
Now, a screen without buttons is pretty useless, so you might expect the E-ink screen to have some kind of touchscreen. PopSlate came up with a better idea. Instead of a touchscreen, their case uses the iPhone's accelerometer to detect your finger tapping on the E-ink screen.
As you can see in the video, the prototype does a pretty good job of figuring out what the users are trying to do. I can only hope the finished product works as well. I don't have an iPhone 5, but I am almost tempted to get one just to have this case.