We’ve updated both the master and grunt branches with Bootstrap 3 RC1. Since BS3 is constantly getting updated, you’ll probably want to pull in the latest LESS & JS from the Bootstrap repo prior to starting on a new site. It’d also be a good idea to track the development:
It looks like demo.rootstheme.com uses Bootstrap 3 already. Great. Really looking forward to the new site and tutorials. @ben to have a tutorial based on building a simple “sample site” would be awesome.
Roots is a starter theme, not a parent theme. If you want to develop with child themes you should use leoj3n’s fork, which has been tweaked to make it more child theme friendly.
It’s probably worth noting that Roots is developed without backwards compatibility in mind, and simply updating with every version will likely break things. This is how starter themes differ from frameworks and parent themes; starter themes give you have a solid foundation to build on, but keeping house is the designers job. A well designed Bootstrap 2.3.2 site will still look and work great after Bootstrap 3.0 is finalised; once the site is complete there shouldn’t really be a need to constantly update every dependency.
If you absolutely must redo your sites in Bootstrap 3, there is a generic migration guide and converter. Just remember that it’s still only a release candidate for the time being, so you may have to redo the sites 2/3 more times before the first official release. Even the grid went through a pretty significant overhaul today, so it looks like nothing is safe.