Microsoft's Sam Glassenberg told Next-Gen in a phone interview, "DX10.1 fully supports DX10 hardware. No hardware support is being removed....It's strictly a superset. It's basically an update to DX10 that extends the hardware functionality slightly."
"All the hardware is still supported, all the games still run, all the features are still there, we've just simply extended the feature set and the lifetime of the API," he said.
Glassenberg also addressed rumors that DX10 -- currently exclusive to Vista -- would be coming to Microsoft's Windows XP. It seems that DX10's Vista exclusivity is unlikely to change.