All I needed to do was rework my use of ZF components to use the new ZF2 ones. Whilst I was at it, I also converted it to use namespaces. I also had to reorganise the http://github.com/akrabat/Akrabat library so that I could have ZF1 and ZF2 code in it.
class Akrabat_Tool_DatabaseSchemaProvider extends Zend_Tool_Project_Provider_Abstract
class DatabaseSchemaProvider extends \Zend\Tool\Project\Provider\AbstractProvider
The filename, DatabaseSchemaProvider.php, is the same and the file lives in the Akrabat/Tool directory as before.
You can see the class now extends from ZendToolProjectProviderAbstractProvider. This shows one of the consequences of moving to namespaces: with a one to one mapping, we would have ended up with a class called Abstract which isn't allowed, so the classname has been changed to AbstractProvider. There are a fair few class name changes like this throughout ZF2, so expect to do a bit of file browsing :)
The rest of the changes that I had to make are exactly the same type namespace conversions and that was all I had to do. Maybe when the autoloader is updated, then more changes will be required and if so, I'll no doubt write it up!