I haven't restarted and used the phone quite a bit this morning for a good 45minutes. My android OS use went down to 25%....wondering why it would be higher when it's idle. I also use Airdroid whenever I'm home and yet the OS % went down...very strange. I hope 4.0.3 fixes this issue, it's not a huge concern, but certainly puzzlingI flashed the 4.0.2 factory image last night to start from scratch... getting much better results today. Still not great, but a definite improvement... Android OS still using too much, but it's a step... this is mostly on wifi, with a couple hours on 4G - and a LOT of usage since I got up this morning.
Dezy mine was like that yesterday too - uber-high...
Also someone in that XDA thread posted using a different battery seemed to make a big difference in Android OS' "keep awake" usage... weird.