Allow Power Query results to be written back to a flat file or SQL table. Relivant forum thread: http://community.powerbi.com/t5/Integrations-with-Files-and/Can-PowerQuery-write-data-back-out/m-p/1...
PowerBI (and Power Query) is getting very close to Killer App status. This would move it along that pathway significantly. There is limited use in a tool that can take data from almost anywhere, perform almost any transformation and then not externalise the result. Note that a lot of other suggestions on this site also arguably would be satisfied by taking this on - and so I feel this feature is under-represented in vote count.
