The one thing that irks me about the console design is the amount of RAM it needs. In the age where 8-bit consoles were actually being built, RAM was the most expensive part of the devices by a far margin. It is no accident that the Atari 2600, for example, only had 256 bytes of main memory, and even the very popular NES/Famicom ran on only 2kB of main memory. This "retro" design, by contrast, employs a lot of RAM chips in a variety of places, even where they are not actually needed: the CPU and PPU can be connected with different technologies (as the article hints at), and double buffering via a second VRAM chip is the kind of feature that classical home consoles would never do due to cost reasons.
Don't get me wrong though, it's still an amazing project!