I sort of know the guy who is creating this (friend of a friend).
1. My understanding is that he's aiming to turn this into a product. No idea when or how much though.
2. Because it taps into the external bus, it won't work on CDROM games (because the external bus is not exposed on any PCE CDROM machine).
3. It also acts as backup RAM, and because it uses non-volatile FeRAM, the values won't disappear in your lifetime. A USB port allows one to read the Backup RAM into a computer, too.
4. I heard that as of a few months ago, there was about 1 frame skip every 5 to 6 seconds (slightly jarring), due to NTSC refresh frequency versus HDTV frequency differing by a very small amount. Other than that, perfectly smooth. His twitter seems to imply that he's been fiddling with refresh recently and improved it since I last heard. Not sure if it's completely solved though; one might need to change the internal 21.xxx MHz clock in the PC Engine to completely solve that.
Personally, I'd love it as a mod to a CDROM machine, but I'd probably buy it (if I still played on original equipment).
-Dave
