This one's fairly controversial but nevertheless a highly-requested feature, that F5 introduce multiplayer to the series, most likely in the form of co-op online play. Many hardcore Fallout fans are firmly against the idea as they feel that it will steal development time away from the world-building and overall scope, while others simply note how many arbitrary multiplayer offerings out there feel watered-down and insubstantial compared to the rest of the game. But come on, it's Fallout! Traversing the wasteland with a buddy or two and taking on missions has the potential to make the experience even more fun, especially if you've all got microphones. Yes, it would be a challenge to massage it adequately into the Fallout formula, but considering that Bethesda did consider it for F4, it actually seems fairly likely that they might give it a go for Fallout 5. Then again, F4 made $750 million in revenue in just 24 hours without it, so the incentive might not be there...