ATI's head of developer relations Richard Huddy claims DX10.1 is projected to be the last and final update to the DirectX 10 API.
The DirectX 10.1 is a relatively minor superset of DirectX 10, but it will last for quite a time, unlike the 2.0a or 2.0b versions of shader model 2.0 that were promoted back in 2003 and 2004 by Nvidia and ATI, which did not become popular due to availability of shader model 3.0.
If Microsoft does not have plans to develop its DirectX 10 further and will concentrate on the DirectX 11 instead, developers of graphics processing units (GPUs) will not need to add any new functionality to their products and will therefore have to focus on performance, rather than on innovation of functionality. But that is hardly a bad news: presently performance-demanding DX10 games, such as Call of Juarez or Crysis, cannot show adequate framerate on current-generation ATI Radeon HD or Nvidia GeForce 8 hardware.
Unfortunately, actual availability timeframe for Microsoft DirectX 10.1, which is supported by ATI Radeon HD 3000-series GPUs, remains unclear. It is expected that the version 10.1 will be featured in Microsoft Windows Vista service pack 1, which is due sometime in 2008.