This is a serious issue, which I hope Apple are making a priority.
After years of iTunes working normally, after upgrading to the most recent version my Laptop fan started deafening me when the computer was apparently idle.
After looking through Windows Task Manager (I'm using Windows 7 64 bit) there was nothing listed as using the 13% of the CPU so I had to dig deeper.
I clicked on Resource Monitor and click sort by CPU usage, at the top of the list was AppleMobileDeviceService.exe using about 13% the only way to fix this issue for me is to manually kill the service, I right clicked it and pressed "end process" and even that took several seconds as though the process was hung.
I can't believe an update has not been sent out yet to fix this issue!
My anger at Apple over this has driven me off Apple a bit, switched my phone over to Android & started selling some Apple products because this is an infurating issue when all my hundreds or even thousands of dollars of content can ONLY be played on iTunes so it made me question how much more money I should invest when Apple can't even make the software work right.
Edit: If they do not fix this soon I may switch completely off from Apple and sell everything.
Message was edited by: Apersonfs