Comment 4 for bug 697129

@Nima-k2:
For more complex migrations, we have been developing a complete incremental migration process, so OpenERP (the Publisher) can take care of migrations automatically as part of the regular Publisher's Warranty contract. This is explained in more details on http://www.openerp.com/services/subscribe-onsite
From what I've heard the migration team will process the first actual customer migrations as of February 2011 (beta tests are already ongoing)

There are also ongoing efforts in the community to develop migration scripts, probably more suited to experienced OpenERP specialists, who are able to diagnose and troubleshoot any data migration/inconsistency issue themselves. I don't know exactly how far these efforts have gone yet, maybe others can comment on this.