After watching the latest sixtyfiveford video I figured I would give an update here. Apparently he got a pre-release model of a battery adapter system for power tools. The batteries use high quality Molicel cells, and the adapters are much smaller than others, only requiring about an extra ~1/4" or 6-7mm. He does a full review and it looks really good. The most important part to me is what he says at the end. He says products like these force the tool manufacturers to just make better tools, instead of locking you in to 'their' batteries, charging a premium.
It makes sense to me. People generally don't buy cars or electronics from the makers of batteries. Let the car, electronics, and tool companies make their stuff and let the battery people do their thing. Especially since most things are already standardized, and many factories are coming online to pump out cells whether anyone likes it or not, I like the idea of battery experts doing their thing and reducing waste, eliminating vendor lock-in, and forcing the tool companies to make good tools. Not just 1 or 2 flagship products and then a bunch of poorly made stuff to fill gaps because people are stuck on a proprietary connector.
The product hasn't come out, so I can't personally say if it is good or not, but it seems really decent and I love the idea. Maybe one day we will just have one connector for each voltage, and perhaps keying so low amperage batteries won't slide in to high current tools. Anyway, here is the video: