I like the idea of having cartidges. I would totally get into that (especially if $5-7 dollar range with about 40 games each).
I think that there needs to be some easy way to load games from a PC or Mac. USB interface to the FB3 or a USB adapter to load games onto a "blank cartridge" would be interesting. If someone develops a good IDE then you'll have folks all over the world writing new games, etc. for it. I know there would be some legal concerns here and I'm not sure how best to handle (ideas anyone?), but I think the ability to load games (disk images and bins) from USB would make it a top seller. You could even sell ALL the games online and not even use cartidges.
Would be great if it could run 2600, 5600, 7800, 400, 800, 800XL games
My favorites:
400/800: Fort Apocalyspe, Blue Max
2600: Armor Ambush (all-time favorite), Pac Man, E.T. (not kidding, I miss the little guy), Demon Attack, Raiders of the Lost Ark, Empire Strikes Back, Race/Indy 500 w/paddles (racing on ice is awesome)
And please sell the paddles and the joysticks on their own or include both in the package. Paddle games rock, and I think a lot of folks wouldn't bother to buy old ones from an online seller.
Packaging a keyboard with it would not be that great of an idea imo. Would be too bulky if was large enough to be practical. I don't see myself or my daughter laying on the carpet typing on the FB3, but who knows...
And on a totally separate topic... I vote for vector arcade classics on the FB4!
BTW - Curt, you rock!