[SkyMarshal]

>What's the win going from 16 to 12 columns?

Was wondering that too. First thing that comes to mind is that 12 columnn is more flexible for responsive layouts, which is another big addition in v2.

For example, since 12 is divisible by 3, it's easier to create a responsive site with 3 vertical sections that collapse into a single vertical section on mobile devices. (Like the Less Framework's mobile layout: http://lessframework.com/. Not the best example, I know I've seen a better one, but can't find it atm, but that gives the general idea.).

Don't know for sure if that's the reason, though.