it would be nice to have the possibility to merge or split instances of piwik.
an import feature from one installation to another should do the trick. maybe one piwik instance could just supply all data for a second instance. the second would then import this data as a new website with an initial dataset from the first instance.
Thanks for the idea, you can post comments on the ticket if your use case is not covered or if you have any ideas to share about how it should be implemented.