The Migration to MySQLi is a multi step process.
The native Dreamweaver Server behaviors where the platform that we used for building our extensions. To begin porting the extensions to MySQLi, the first step needed to be to recreate the native server behaviors.
Now we are working on adding MySQLi support to our other extensions. eCart was the first to be completed, and we will be upgrading design Extender and Data Bridge as well.
As for having to recreate pages, the simple answer is: We don't know yet. Ray has made mention of creating a migration tool, but I don't know what the scope of that will be as it is not yet finished.
I Dont have a time frame for when the other extensions will be released for MySQLi support, but announcements will be made when they are.