Today Microsoft officialy released DirectX8.2, it contains DirectX 8.1b and some DirectPlay bugfixes :
This download contains DirectX 8.1b plus some DirectPlay fixes related to performance and connectivity issues exhibited with some online multiplayer game titles. This release of DirectX is not recommended for general installation. You should only consider installing this release if you have an online gaming problem that has been identified as being fixed with DirectX 8.2. This version of DirectX can replace all previous released versions of DirectX.