トップページに載っていないので目に付いた変更点といえば,Boost Configuration Libraryで定義されるマクロのうち,informationalhelperについてはBoostの開発者同様,ユーザも使用して良いと正式にドキュメントに記述された点か.

Boost informational or helper macros are designed for use by Boost users as well as for our own internal use. Note however, that the feature test and defect test macros were designed for internal use by Boost libraries, not user code, so they can change at any time (though no gratuitous changes are made to them). Boost library problems resulting from changes to the configuration macros are caught by the Boost regression tests, so the Boost libraries are updated to account for those changes. By contrast, Boost library user code can be adversely affected by changes to the macros without warning. The best way to keep abreast of changes to the macros used in user code is to monitor the discussions on the Boost developers list.