In my little business, I get a ton of people telling me what I COULD do, and no doubt you guys are getting lots of that. But I had a thought yesterday while riding. Tandem. AI+ real person tandem = weak gal keeps up with strong guy. Person + person tandem = I can ride with my GF across town = social impact = stay together while enjoying Zwift.
Hi Steve,
You can ride tandem in Zwift! Just make sure you both log in at the same time and you can ride together 
The AI riders are there to just help populate the island.
I had the same tandem thought. Adding a virtual tandem would really add to the social side. This might be a little out there, but it would be fun to have a sort of alternative course/section that would allow for things like 8 person-per-team beer/party bike races where the combined power drives the vehicle. You could also do “interval” games like rickshaw races where one person captains the bike while the other rests for a fixed duration before they switch again. This would also work for “little 500” races and the like (which I am sure you have considered).