I imagine in the future when Ore becomes stable, a plugin could scan all existing plugins, find the relevant Ore page, and check for updated versions.
Until a central repository like Ore exists, however, it would be utterly painful to implement any plugin-wide version checking (like relying on the forums).
Continuing off of what @ZephireNZ said, I recall that somewhere the dev team of Sponge itself hinted at the future release of a plugin for plugin management (updating, downloading, etc.) from ore.
Well I wouldn’t suggest scanning them all. Instead just give the plugin a namespace/id within that Ore instance and check specifically for it. Otherwise what if we have hundreds of thousands of plugins/libs?
@varrix
Ore is intended to be functionally equivalent to a Maven repositories for every plugin (at least on the back end). So yeah… they will have a namespace/id.