The Bulk Extensions module has now been updated to work with FreePBX 2.5. Some big changes happened between FreePBX 2.4 and 2.5, so you may not be able to directly export extensions from 2.4 and import the unmodified CSV into 2.5. However, you can definitely modify the CSV to get the import to succeed!
Download link:
http://freepbx.org/trac/browser/contributed_modules/release/bulkextensions-2.5.0.1.tgz