Decoupling the browser from the OS is one of the best things that could happen for android security going forward.
Decoupling everything but the most rudimentary services is the best way forward for both security and user satisfaction. Despite the laser focus on the underlying operating system version by so many, tens of millions of Android users, across makes, models, and carriers, are seeing endless updates of mapping and navigation, the search functionality, the mail applications, the Android market, and so on. Decoupling the browser adds it into the bin of "no longer need to care about the underlying OS much", and goes a long way to make the fragmentation issue a non-issue.
If the core services are going to be different then the fragmentation is still a problem for app developers. May be not so much for the end users but I guess the end users don't care as much.
Not everyone will update frequently or would want things to get updated for them without them knowing it. Certainly not the non-techy users. This makes it a pain to account for all different versions of browsers, OS, resolution and other functionality a pain.
Decoupling everything but the most rudimentary services is the best way forward for both security and user satisfaction. Despite the laser focus on the underlying operating system version by so many, tens of millions of Android users, across makes, models, and carriers, are seeing endless updates of mapping and navigation, the search functionality, the mail applications, the Android market, and so on. Decoupling the browser adds it into the bin of "no longer need to care about the underlying OS much", and goes a long way to make the fragmentation issue a non-issue.