[psidnell]

OK - I'm using FreePlane not Freemind, so YMMV, and this is a little circuitous and requires OmniOutliner but:

Export your mind map as XSLT and specify OPML as the format.

Open the OPML file in OmniOutliner, open to full depth and copy the root.

In OmniFocus create a new project, a new empty task and select the row handle and paste.

Voila.

I did try pasting a branch directly from FP into OO but it didn't create nested tasks, but rather created a flat list with depth represented by leading spaces.