A group called Bristol Braille Tech is trying to release a mechanically refreshable Braille eReader named the Canute. Link below.
http://bristolbraille.co.uk/canute.htm
From the video on the website, it appears to be about the size of a standard US keyboard with a numberpad, maybe a couple inches deep, and from the website, "It will be 32 cells by 8 or 16 lines and cost less than a Perkins Brailler or iPad Pro." In addition to the cells, it has eight face buttons, four on the left and right of the lines, with a USB port on the side for ePub files and other book formats.
The important part, for me at least, is that the code to the device's UI has been released to Github, meaning that it doesn't just have to be an eReader, and dedicated applications and games can be developed for it. It appears to be running on a Raspberry Pi, so there's more than enough power under the hood to be creative, and a great developer community to pull from, but it's all still specifications and prototypes right now.
For the users of /r/blind, is it worth pouring new iPad or brailler money into a dedicated Braille eReader? And were there to be custom software for the device, what would be an absolute must have?