Microsoft has released DirectX 9.0 Release Candidate 0 to their official beta testers at betaplace.com. No doubt it will leak before much longer.
This is a Release Candidate 0 (RC0) of Microsoft's DirectX 9.0 Software Development Kit (SDK). It contains all DirectX software required to create DirectX 9.0 compliant applications.More information @ Warp2Search
Major components include: DirectX 9.0 system components (runtimes); DirectX 9.0 Application Programming Interface (API) Documentation for each of the DirectX core areas (written for C++, C#, or Visual Basic developers); DirectX 9.0 headers & libraries; Sample applications and source code; miscellaneous tools and utilities.