Would be nice to have access to power management support of the OS to check battery status.
Definitely not a 'core' feature but useful for fullscreen games that obscure the native OS indicators.
Example:
http://hge.relishgames.com/doc/index.html?main_power.html
This seems like an obscure feature to me. I don't know of any games that do something like that (aside from the one you posted ;D)
It would be kind of cool to do that, though. 8)
That sounds like something not directly related or relevant to the graphics library itself. Does OpenGL provide such features? From a quick glance at the OpenGL Programming Guide, I think it doesn't.
I personally would expect power management info to come from a dedicated library. The user would then decide which action to take by the gathered info if he chooses to inside his own code. Looking at it that way, LWJGL shouldn't provide that info at all.
But I can't find any such library, apart from the Power monitoring feature of the Java Phone API.