Well... there's no battery meter on the shuffle, so checking that way is out :-)
However, I do note that the lights on the shuffle behave EXACTLY the same way whether it is plugged in to the dock or the Incipio dongle. First the orange light blinks, to indicate that it is syncing, then it is solid orange, which allegedly indicates charging. I'll leave it plugged in for a while and see if the light turns green.
Now if I could only find a case just big enough for the shuffle and my Shure headset.... Everything is too big, LOL.