I have a crap ton of unused memory cards and under-utilized hd-disks. It would be nice to have a Storage Hub on the network to which you could attach a bunch of storage media (USB drives, SD cards, HD-disks).

Just a single view of all my storage media. Sweeter if it came with DLNA support.
Not NAS though. A lot of them are insanely expensive and come with fancy RAID pants.

Considering Pi3 or Chip at the moment.