I'm going to take an educated guess and say no. Look at it this way: if you try to charge your iPod via a hub, your computer gives you a messag telling you that the hub doesn't supply enough power for the USB unit, or something like that. I'm guessing that the Wii works the same way.
But look at it this way: You probably aren't going to have to charge all four Wiimotes each night. I tend to last about 3-4 days on a single charge (normal 3V battery pack). So even if you manage to finish up the batteries of two of your Wiimotes in one day, you can still charge.
If, however, you need to charge more than two Wiimotes daily (I don't know why you would, but still . . .), you might want to consider charging with your PC's USB ports. Another option is to buy a USB - Power transformer. I originally bought one of those to charge my iPod in the wall, but I have discovered that it works for charging any USB product, I even used it to power my USB Christmas Lights in December.
Hope I helped