Minimum system requirements suggest it may be possible if ported with 100% efficiency, which is unlikely for the N900s lifespan. But never say never, someone with sufficient talent could make it work. DirectSound might be a roadblock though.
"If you want to run your own server for the game, you have the software to do that, but you won't really have any world data—information about geography, special places, characters, quests, items, and so on—to run it with. Winch Gate Properties, the company that currently holds the copyright for all game materials and runs the official server, has decided not to release that data, to avoid causing disruption for their current player community. People who want to run their own server will need to develop their own world to do so—only a small test world comes with the code."
I don't think content will be the issue with this one.
"Developers can now access the source code of the end-user client, content creation tools and server in order to make modifications, enhancements or to create their own virtual worlds."
