I think this would be great addition for XF 2.1. I don't see this as being a realistic expectation for the 2.0 release. A Xenforo Page Builder is a missing link in the platform. It would also make it easier for Skin devlopers to design custom homepages.
A lot XF users would love to ditch their CMS to create a fully interactive homepage right in Xenforo. I realize it's possible today with custom developement, it's also ridiculously expensive to get a developer to design a Xenforo based homepage.
Is there any interest in eventually adding a page builder to the Xenforo platform in the precieved future?