and Frank horrigan coming back would cause me to S!$# my self in terrier!!!!!!! cuz if a NUKE CANT DESTROY HIM WHAT WILL!!!!!!!!!!!!
http://www.katties.se/images/2008/jack-russell-terrier_3156364.jpg
I think an optional turn-based system would be cool, like how you enter VATS and you aim for body parts (eyes and groin again, please! And for melee aswell!), and when you are done using up your AP attacking, it's the opponents turn to use his AP targeting your, or your companions, body parts. And then your companion targets some enemy's body parts for his AP... and so it goes. Would be coolest when there are many opponents. Always feel better coming out from a fight in turn-based versus three times more enemies than it does in FPS because then you don't have to worry about if you've put skill points in the right skills, and any perks that enhance AP, AC and whatever, and that your character is better than the enemy characters. In an FPS you just need to worry about having a good weapon, and your own aiming skill.
I also think a node system would be cool. It would make the game world feel sooo much bigger if you could travel across states! I mean, Fallout 1, 2 and Tactics cover states! Fallout 3 and NV just cover a part of a city and the surrounding area. I think it would be cool if you could choose to walk through the wasteland (wasteland would actually be a wasteland, a nothingness, just unfertile earth, ruins and junk under the hot sun or raging storm) between the "points of interest", the nodes, which would be... well, settlements and the surrounding areas that may have anything interesting, but also, you know, caves and buildings/towns worth lootable, and quest locations, and faction HQ's... such things. There could of course be as much, if not more, "points of interest" (that is, playable area with something interesting, like, say, the world map of Fallout 3) than in Fallout 3 or Fallout NV.
Also, the implemention of different vehicles and mounts would help with travelling these distances. Having a horse, a donkey, a brahmin, a giant mole rat, a jeep, a motorcycle with a cart, a truck, or a custom-built vehicle (or a Chrysalis Motors Highwayman!) would speed up travelling, and also make it more funny in real time (well, not maybe riding a donkey or brahmin across a wasteland and town ruins) and you'd also be able to bring a lot more stuff, and some companions.
Edit: On the topic of distances between places in Fallout 3 for example. I thought it felt pretty stupid when... that blonde chick in Megaton... hands me a letter for me to deliver to her parents in Arefu, and she doesn't go herself because it's dangerous and whatnot. When she said it, she made it feel like it was a long way there, to some settlement, like in Fallout 2 when they say "That town lies south of here, a three days journey" or something. But they way to Arefu was only... a little walk away, it felt.