One thing I could see with this engine is the ability to actually be able to buy land. Useing two types of credit systems. One credit system would be the game world money, and the 2nd be buyable money that players can go onto a site and buy these credits with real world money.. With the second credit system players could then use the 2nd money system to buy land from players. And or the developer himself. They could also use this credit system to sell stuff as well to other players.. Like say property with base's and stuff already on them.. Then they could turn around after say some one baught there base. Send the credits as real world money back to there own account. Pay pal ect Players could actually buy and sell stuff in the game and soon turn up a liveing buying, and selling virtual property and or objects to one another. Sort of like second life.
If done right the developer of this engine, and also players could make a huge living off this engine.Though the exchange rate would need to be setup. Like you buy the credits for more then you get when you put them back into your account as real world money.
Like say 50 real world dollars with get you 1000 game credits.. But to get 50 real world dollars back you would need 10,000 credits. ect
There are a few examples of these, I think they are called "Real Cash Economies", out there.
Like you mentioned "Second Life", and also this really bad game IMO, called "Entropia Universe".
The latter being a total rip off by the way. One can buy virtual land there,
but you have to spend like 10.000$ real dollars for a small piece of it. You can set taxes on it, so players whom happen to mine and hunt on that land, have to pay the owner a certain percentage of their loot value.
But the system is so flawed there, oh gawd
Only a very small percentage of the players there make some money off the game, namely those who own an attractive piece of land, the rest will always lose. It is designed that way.
"Entropia Universe" being an example of how it should not be done IMO, lol.
Personally, when it comes to games or mmorpgs, I like a system more where one pays a set monthly fee and everything else is basically up to you and not to the contents of your real life wallet.
Or a play for free model with the possibility of a premium account, if you want to pay a monthly fee.
For example, if you dont have a premium account, you cant own land etc.