According to a recent post at Slashdot, it looks like Direct X 9.0 will bring to a close the saga of DirectX Graphics. New APIs that are part of Windows Graphics Foundation and Avalon will take up where DX9.0 left off.
"Microsoft will still rely on DirectX in name for the rest of the core components, but the graphics API is now under a new name."
Certainly the end of an era. But then, we've all come to take Microsoft's future plans with a pinch of salt, so just wait and see what happens.