Dive summary: 

• Mozilla has decided to put the browswer update that would make blocking cookies the default on hold; instead they will keep cookie blocking as an option to opt-in. 
• The company has decided to test out the cookie-blocking by allowing users to opt-in and study how the patch works on real sites. 
• The default security patch is still in the works for Mozilla, but the controversy surrounding the announcement that their "do not track" feature would be default. 

From the article: 

"'There are many conflicting claims about how this patch will affect the Internet,' wrote Brendan Eich, co-founder of Mozilla.org and CTO and senior VP of engineering at Mozilla, in a post on his personal blog today.
'Why debate in theory what we can measure in practice? We are going to find out more and adjust course as needed. This is the essence of the release test cycle.'"