Microsoft Demos "Deep Zoom" Technology
Yeah, that's pretty much mipmapping. Except the primary difference is that Microsoft has discovered a way to take this decades old 3D technology, and apply it to 2D... after everybody already had... for a couple decades.
BTW, they can also be called thumbnails, or progressive JPEGs, and probably something else too. I'm probably forgetting some important things in computer history that could be cited as examples.
But nobody else has done it in SilverLight!
I didn't look that closely, is there a patent pending stamp in the lower right corner for this amazing invention?