According to Tateru Nino at Massively, the Lab has made and released changes to the third-party viewer policy at the request of the opensource-dev community. Sadly, however, they still f*cked it up.
The only change I see, on a casual read is this sentence in the third paragraph of the preamble: "This Policy does not place any restriction on modification or use of our viewer source code that we make available under the GPL."
But still, that sentence directly conflicts with Section 7(d), "You assume all risks, expenses, and defects of any Third-Party Viewers that you use, develop, or distribute.", which violates the GPL's disclaimer of liability.
The best and shortest response I've heard from the open source community makes what they think of the "rewrite" crystal-clear: "You first", as in "If you want us to take responsibility for our viewers by violating the wording of the GPL, then change your ToS(Section 5.4, specifically) to do the same for your own viewer as well".
Now that the Lab has stated that they will not be planning any further modifications to the policy, the ball is now in the third-party devs' court to decide what to do in light of it. Boy Lane(developer of Rainbow viewer), and Fred Rookstown(developer of the Luna viewer) have already stated their intents(Both have simply called it quits on their viewers). Tomorrow the Imprudence developers will meet in-world to discuss what to do regarding the policy, but there's a strong possibility that most popular viewers may abandon SL altogether and throw their weight into OpenSim-based worlds in order to avoid being shackled down by LL.
As TigroSpottystripes Katsu put it: "It's own-foot season, and this time LL brought the big guns."