According to Eich's post:
"ORBX.js, a downloadable HD codec written in JS and WebGL. The advantages are many. On the good-for-the-open-web side: no encumbered-format burden on web browsers, they are just IP-blind runtimes. Technical wins start with the ability to evolve and improve the codec over time, instead of taking ten years to specify and burn it into silicon."
"After these come more wins: 25% better compression than H.264 for competitive quality, adaptive bit-rate while streaming, integer and (soon) floating point coding, better color depth, better intra-frame coding, a more parallelizable design — the list goes on."
The part about evolving the codec without changes needing to be burned into silicon refers to the fact that ORBX.js can serve as a replacement for the hardware upgrade cycles that have typically been involved in improving video and graphics performance. As Information Week notes:
"The code library, ORBX.js, can be thought of as a cloud-based alternative to Google's Native Client technology. It permits Linux, OS X and Windows applications to run on remote servers and to be presented in a Web browser....a development that has the potential to make computing hardware less relevant and to diminish the gatekeeping power currently enjoyed by Apple and and Microsoft."
It's well worth watching the videos that Eich has presented online, which show side-by-side speed comparisons between ORBX.js and competitive technologies. The results are impressive.
For all the Iron Man fans out there, Eich even proclaims: "This is Tony Stark stuff."