VirtualBox's competitors are also replete with clever integration features like replicating documents and folders across both physical and virtual machines.
This is where cloud-based offers and services will definitely ease the integration process, by centralizing profiles, documents, data, information and knowledge in the cloud.
And while we're at it, ASUS' WebStorage also offers instant photo uploads, Microsoft Office Web Apps integration (so you can edit Office documents online using the official interface) and file collaboration.