The in-light rechargers will likely also mean a proprietary battery format. 4sevens recently went this way. It's probably done for safety, and perhaps ease of manufacturing. 4sevens probably doesn't want people putting an Ultrafire in their sealed light and charging it until it goes
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When your battery dies, you'd better hope the company is still in business AND is still making those proprietary batteries. In 3 years, when you need a new battery, what do you think the chances will be that your light is still being made? If your light isn't being made, there's not much reason for the company to still make batteries for it.
I think it all leads to manufactured obsolescence. Throw away your light in 3 years, because you won't be able to power it any more. Maybe that's good for the flashlight companies (they get to sell Joe Sixpack another light), but it's not good for the consumer.