Another twist in the YouTube - Viacom copyright issue - from
the BBC:
In court documents Google's lawyers say the action "threatens the way hundreds of millions of people legitimately exchange information" over the web.
The search giant's legal team also maintained that YouTube had been faithful to the requirements of the 1998 Digital Millennium Copyright Act and that they responded properly to claims of infringement.
Hmmm....this can be more accurately stated as threatening the way hundreds of millions of people exchange media illegally on YouTube

Also, YouTube adheres to the DMCA in the sense that when there is a takedown notice it takes down that infringement, content in the knowledge that someone else will soon repost the content back up.
The real news here is that Google is going to use its considerable resources to hold up any attempt to clamp down on YouTube for as long as it can:
Google's vice president of content partnerships David Eun has said: "We're going all the way to the Supreme Court. We've been very clear about it."
In other words, this will still take some years to resolve, and in the meantime YouTube can continue to make hay - no doubt in the hope that in the interim either:
(i) Copyright Law changes to reflect the new realities
(ii) Google / YouTube find an alternative business model.
(iii) The media industry won't find a way to block the copying of content
This is - in my opinion - a rather interesting bit of game theory now. The cost of going to court to either party is not a major cost in their worlds, so both will continue on this path. The outcome has massive impact of course, but is several years off, so both sides will be thinking about how to mitigate worst case outcomes. They will thus be looking at conflict as well as collaboration in their strategies.
The best mitigation for both, however - the lowest total risk outcome - is probably to move towards some form of compromise position over time. Google knows that it will probably eventually lose with its position as things are, Viacom knows that it can't re-bolt the stable door.
So, expect lots of posturing, but the slow hammering out of a
New Accord for copyright.
Update - Ars Tech has an
interesting summary here, but I don't agree that Ars Tech is in the same boat - I think there is a huge difference between them and YouTube.