Seriously though, I don't recall any real or implied commitment from BMD to address this particular feature request.
True that BMD has not made an explicit point to add that but I believe that most, if not all things that came with the 1.1 update were unannounced as well.
Ordered From: B&H Order Date: 09/16/2012 Delivery: Not yet....
The "Disk Full" indicator is flashing when the SSD is almost full, said the camera manual, page 16. However, a more precise indicators would be very useful (at least like the battery one : 25%, 50%, 75%…).
This is something that will undoubtedly be fixed in a firmware update, eventually. In the meantime, the math is pretty simple to figure out. You should be able to work out when your drive is roughly 75-80% full pretty easily.