Don't go turning this "wish list" into facts.
You can't highlight "including harmony cart and homebrews" and make it true.
It says, "things we can hope for."
The lastest Retron HD was hardware based, unlike the Retron 5. I did a review of it on my channel. I predict that this console will not be any different. I am very interested in this and excited to see this announced. A couple of things that we can hope for.
1. Plays near 100 percent of library including harmony cart and homebrews.
2. Cart port that can accept all third party cart designs.
3. sound and color accuracy
4. System durability
Between this, the Atari Box, and the Atgames hardware I would say that this is a great time to love Atari games.
I'm not usually this negative, but I'll point out when things are taken incorrectly.
I do not know what "hardware based" really means, but the Flashback 2's approach almost got it 100% right except for one thing :
Needed illegal opcodes added.
The fact that adding a cartridge connector doesn't play more real carts was found to be due to a change that was implemented late in production and not from the designer. If the production didn't change the original design, all bankswitch and extra ram carts would play. Need proof? It plays the built-in Millipede which has Sara RAM but the real cart fails. The Flashback 2 is capable of playing all games that do not use illegal opcodes with 2600 accuracy.
If RetroN 77 is recreating the Atari chipset, which is the easiest approach with a good chance of being close to 100% accurate, then it will a retro-gamer's dream come true.
The past has shown "Nintendo on a Chip" to be good, "Atari on a Chip" to be good, and "Sega on a Chip" to be bad.