There is a new release of B2 and there are some important changes..
* The build-build.jam file, and the build-system rule,
used to specify where to find the build system Jam file is no longer used for that purpose. There is now an internal method for finding the corresponding build files relative to the b2 executable. This means that the preferred method for using B2 is to install it first. But, the regular bootstrap use in Boost is still supported.
* There is now a Windows MSI installer available that supports both per-user and per-machine installs without having to build it yourself.
* Installing the current, and future, B2 allows one to use the newest B2 with current Boost release and most older Boost releases. And of course the same goes for non-Boost projects.