I found that short post but it doesn't explain which memory savings are due to DX10.1 and why. It also mention features (e.g. color hot track, enhanced thumbnail animations) which work fine with DX10.0 hardware as far as I can tell.
So I'm not sure the page intended to imply that DX10.1 hardware was required for any of these improvements. (And if it was, maybe that changed since.) That's why I wonder if there's a more detailed description somewhere. (Perhaps in the video it links to but it's 73 minutes long and I don't care that much.
Just curious.)
Also, do the relevant parts of the DX10.1 API require DX10.1 hardware? The API improvements in question could all be at the software level and not require hardware support. (Never written any DX stuff so maybe it doesn't ever work that way. I don't know. But I could see the improved API offering benefits even on older hardware, with only some of the new API features requiring new hardware.)