It's not 100% decided yet, but if we issue a Firefox 3.6 as a minor  
update, then yes, we'd stop supporting the 1.9.1 branch at that time.
There are several confounding issues with this approach, however, the  
most notable being that Seamonkey and Thunderbird will be based on  
mozilla-1.9.1
cheers,
mike
Archaeopteryx
Yes, of course; we are taking steps to ensure that we have a high degree of Add-on compatibility prior to shipping, and this will be part of the decision matrix used to decide how we present Firefox 3.6 to users.
cheers,
mike
Also, some minor functionality was removed from 3.6/1.9.2 that is still 
in 3.5/1.9.1, and of course some was added - I wonder how people react 
to those changes by an automatical "minor" update.
Robert Kaiser
Yes. I don't understand how we can issue 3.6 as a minor update given 
this problem. (And it's not just a version numbering issue, there are 
extension-breaking changes on the branch, right?)
Rob