Ideas I would like to see...
1) A holster. The DeWalt holster is way too large for the 12v Max tools!
2) Flashlight. The one that comes with the tool kits is nice, but I do like the style of the 20v Max one.
Maybe a smaller version for the 12v Max batteries, or an adapter.
3) Multi-Tool. Maybe others would prefer a 20v Max version, but a smaller one would be nice for things around the house.
Light weight, with a tool-less design for blade changes.
4) Circular Saw. Just like the Multi-Tool... small and light weight.
5) Finish Nailer. I know, this is a pipe dream, but a 16 gauge nailer in the 12v max line would be perfect.
Maybe with a magazine half the size of the big nailers. For small projects around the house, finishing
two or three batteries means it is time for a break! :-)
6) Radio. It wouldn't necessarily have to charge batteries, but possible work with the 12v or 20v line.