Sure, but Nokia (at some level) is well aware that their chargers draw well below 1/10th of one watt at idle. They know that it costs pennies to keep the thing plugged in all year. The issue is a political one in that some misguided tree huggers (the green movement) is being catered to, or one of the "Green" maemo programmers thought it worthwhile to add that message without fully understanding the reality of how the hardware performs.
I'll add my findings to the bug. Hopefully some intelligent people within Nokia will understand and take action to remove this nagging, pop-up text message.