iPads have never officially been charged from USB ports. You get a dialog "not charging", but leave it overnight (even with the laptop off) and you will get *some* charge. It's just very slow.
I also did the upgrade, and only have had two issues:
you can't click the power icon to change your power plan anymore. You need to go into power settings in the control panel to do it.
I don't like that windows update downloads updates by default and can't be changed. I liked the "notify to download" setting better. Still, Windows 8 only notifies that there are updates from the lock screen, which is inferior to windows 7 behaviour that actually notified you in the tray.