Notch's recent post about mods.

...
This is what I am afraid of

• We retain the right to use your mod idea and implement it ourselves in Minecraft. This is to prevent the situation where we have to avoid adding a feature just because there’s a mod out there that does something similar. It’s also great for dealing with bug fixes provided by the community.
• You can’t sell your mods or make money off them unless you’ve got a separate license deal with us

So...how, in the future, will my server contain uniqueness and have the ability to pay for itself?
Notch left me a really big issue here...