I would love the experience, but they would need to make it different than other mmorpg. It can't be like Guild Wars. You should be capable of forming a party, but for world exploration i shouldn't be too necessary. You should be capable of fending off enemies on your own or with two people. Also, you should have a much more flexible and personal battle system, more like ESF than Guild Wars. Because Guild Wars is too static in fights. Free roming movment should be allowed. Worlds would have to be huge, but because of that you would need things low poly and less detailed. If you're capable of flying, there should be a medium height ceiling and there should be physical barriers your character can't penetrate. Certain skills like flying must be earned to increase and limit exploration. It should not begin like DBZ, where your character is already a seasoned warrior. You should start out like Goku did in Dragonball, just a really strong newby and make your way up. There need to be LOTS of levels to reach, not like Guild Wars which has a maximum of 20 levels.
Also, you should have a customizable special attack designer like in the THUG games. There should be categories for blasts, beams, saws, special melee, etc. And of course there should be special ways of limiting these attack's power. Of course, some skills can be learned and customized in slots so you don't automatically have every attack.
You should be incapable of going back to any town/city automatically until you learn Instant Transmission.
There should be (like in Guild Wars) a basic storyline for your character to follow. It should involve being killed at one point so you can go to Otherworld as well. Once you get Instant Transmission, you can explore Otherworld whenever you want.
When you gain levels, you should gain skill points which can be added to certain categories, like melee, attack speed, energy blast strength, etc. You should not be able to customize energy and health maximums which will increase at every level.
In towns and cities (like Kami's Lookout) you should only be capable of walking and running, so that players aren't everywhere. You can intermingle with characters here. Eventually, you can create your own warrior team, name it and buy a "safe" meeting place for it. You can add new recruits and have up to twenty memebers, so that the team can't bulge into an organization.
Part of the story should be finding the Dragonballs. Dragonballs are non-tradeable story/quest items, so that a player can't have two four-star balls at the same time, or give a player their extra Dragonballs and make a wish.
Only the player who has gathered their seven Dragonballs can mae a wish, and wishes can only be made outside of towns so that servers won't lag. The wishes should have some real value to the player, as after they first collect them in the story, they will appear in randonmly designated places. Each player should have a Dragon Radar that will give the general region a Dragonball is in, but will not specify its exact location. The Dragonballs will be well gaurded according to the player's current level, whther the area they are in is full of weak or strong enemies.
The world should be vast and therefore must load in a way similar to THUG 2, where the map loads new regions as you go. This will change hen you enter towns or cities. You should have differet paths according to your secies. If you are a Saiyan, your quest will eventually lead you to certain regions in the story that will bring out your Super Saiyan form, sort of like becoming "Ascended" in Guild Wars. Afterward, the Saiyan levels will be achieved based off your level.
Saiyans should conraditory to the story, be relatively weak while normal, so the transformations will balance them compared to other human, android or alien players.
Whoo! A lot of typing! I doubt a fan could make something like this, but if ever Atari decided on something like that, I'd be playing it dawn till dusk! You can count on it!