Also, pretty much any comparison people make is using x264, far and away the best encoder, that unfortunately lives in a slightly grey world. I'm sure comparing the best vp8 implementations vs the worst h264 (ie. the proprietary) implementations would give a different angle.
EXACTLY
Look no further than the same blog Steve Jobs linked to:
Jason Garett-Glaser did a comparaison of encoders this last summer,here were the results:
http://x264dev.multimedia.cx/wp-content/uploads/2009/08/quality_chart1.png
VP7 was already well ahead of Apple's H264 encoder (the one most mac users use) and I'm sure VP8 will be even farther ahead.