No it doesn't. I charged my 10.1 TAB off PC USB. It needed a $2 adapter (or modified cable) and it was slow but overnight it would fully charge. Same for the iPad (no adapter needed). It charges without problem (other than speed) off USB despite the fact it shows "not charging."
Hmm last time I tried charging a Galaxy Tab from a USB charger it kept draining...I ended up having to find the wall unit to charge it.