4pin Power Connector Question

With a Micro-ATX board, I had to use the 4pin power connector to get the computer running with an AMD Athlon CPU. And my friend had to do the same. Yet, if it's a regular ATX board, you don't need it. Is this a standard now?

Yes. Today's mobos draw their power from the +12v rail, but if you look at the "ATX Power Pinouts" thread, you'll see that the standard 20-pin ATX connector only has ONE +12 wire, so the ATX12 connector (the little square one) was created to alieviate the problem of not having enough +12 wires.