What exactly are you picturing as such a mash-up? The critical element of EVE that makes it what it is isn't the economy: it's the ability to take ownership of land by force. That's what creates emergent politics. AFAIK, neither UO or WoW have this. The only fantasy game that has considered this was Shadowbane, but they had a bad release.
Wurm online has this. The reason why you probably have never heard of it is that it is too realistic. It takes days to build a house for example. The creator of minecraft used to work on it, I found out later.
