If we're concerned about preserving our history we might be able to migrate it to a git repository, then convert the markup: https://github.com/mgaitan/moin2git
We run MoinMoin 1.9, but 2.0 supports [exporting to MarkDown](https://github.com/moinwiki/moin/commit/5edfbc2a3e3a8720fad8b2158d67133c2e7b6393#diff-42217d84820d3bab44de675d13077ae9).
Perhaps we could upgrade a copy of our current wiki to Moin 2.0, and then export?