Well it looks like Apple updated the HL-5070N driver on 10.9, so the old technique is no longer necessary.
The date of the new driver should be: Dec-6th-2012. i.e.
ls -al "/Library/Printers/PPDs/Contents/Resources/Brother HL-5070N series.gz"*However* you need to make sure when adding the printer, DON'T select the nearby autodetected printer BUT "Add printer or Scanner" instead".
Select the printer that appears and make sure that the "Use" drop-down has "Brother HL-5070N BR-Script3" rather than "Brother HL-5070N series CUPS".
The "CUPS" one is the one that is selected when you use "Nearby" printers and doesn't work for me at least.
Let me know if you this works for you.
