Hello Bunny and welcome to Flarum ?
There are plans to develop an importer sometime after Flarum has reached the final version. This is true with most of the importers currently pending, as it makes no sense to start working on an official importer until the code here is finalized. Once the code is finalized, importers will be made in the order of community demand and of course, compatibility.
Thankfully, you're by no means the only person seeking an importer to migrate from Discourse to Flarum. It has been requested more than a few times in the past and even the staff here have recognized how similar they are to one another. https://discuss.flarum.org/d/298-migrate-from-discourse/2
As to when!? When it's ready. ? I wish I could give you an exact date, but The Flarum Development Team want to make sure that things are done right, as opposed to rushing to great a deadline.
