TFS 2013 Update 2 has been released!
Microsoft has enabled a method for VSOnline Early Adopter account administrators to export their data for use in their own Team Foundation Server 2013 instance. To receive this capability, send email to: firstname.lastname@example.org.
For more details please refer to the Early Adopter FAQ.
You have until May 20th, 2014 to export your data. For more information regarding the move from VSO to an on-premises TFS 2013 Update 2 see this page.