If Im watching a film or downloading I turn the controller off although it is a bit of a pain to do and I often forget.. I would be great as you said if it turns off automatically after a set period of time when not in a game.
As for that test I think its really flawed because you cant really compare all those controllers because they are so different..
Firstly the PS3 one recharges and the others need batteries so already the power source is not a like for like comparison.
The Sixaxis runs on bluetooth whilst the other are on radio (or whatever its called), Im sure it takes more power for bluetooth... it also has a ridiculous range (I can turn the PS3 on from outside my house!).
The Sixaxis has tilt and the X360 doesnt, but it has got rumble so its not really equal, also the Wiimote has a speaker.
AA's will always last longer than recharge but im not gonna go through the hassle of buying or charging them, if your Sony one eventually dies stick in an new after market one (which they are already making).
Basically what Im saying is that there is no winner or loser as they all offer different things! I would rather have tilt, lightness, bluetooth and a shorter bat life over fiddly batteries which are heavy and using on old form of wireless interfacing.
Robin