I think it is an interesting concept. Don't really see it as essential given the way these tools are likely to be used, but think about this: battery packs are constantly getting bigger and higher capacity, which is cool, but these huge powerful batteries can be pretty pricey, and somewhat bulky and heavy. If you were working in an environment where you will almost always be within arms reach of a charger, though, that huge battery would be kind of redundant. Would you accept a 1.0 ah battery for a cordless impact gun if it were a third of the cost of a 4.0, 1/2 a pound lighter, and is able to run nearly indefinitely thanks to inductive charging? That might make it a much more appealing concept. What about using some form of capacitor in this role, and not use a lithium battery at all? Not a be all end all solution, but for a user who is going to be working in a set location, maybe an interesting concept.