SharePoint 2013 App Model Support for NW 2013?

I remember seeing at the SharePoint Conference in November of last year a proof of concept version of NW 2013 that ran using the SharePoint 2013 App Model. Just so I am clear on what I am asking. The SharePoint 2013 workflow engine has been rewritten and moved to run outside the farm to provide better performance and scalability. Will Nintex be doing the same with the NW 2013 product? Will you re-architect your product to support the new SharePoint 2013 workflow? Can you confirm today that you are using the SharePoint 2010 workflow in SharePoint 2013 today?

Thanks,

Howie