Blogger David Hawley has apparently uncovered, using a hex editor, the future of Nintendo avatar pants: "Special Miis" with pants of gold. If you can get your Mii over to your PC, then you can edit it in hexadecimal to create such a Special Mii. Special Miis cannot be copied, only moved; if you try to put two identical Special Miis in a Plaza, they will disappear.
He has also figured out how to make "foreign" Miis, who are adorned with the blue pants worn by Miis made in other people's Wiis and visiting your Plaza. We have yet to verify this with our own Miis, so be careful when performing code surgery on your Mii.
We wonder what Nintendo thought gold pants would be an appropriate reward for. Maybe they're planning a Studio 54 Channel?