But on the other hand, it looks like DX10.1 doesn't really add that much:
But these gamers shouldn't fret too much - 10.1 adds virtually nothing that they will care about and, more to the point, adds almost nothing that developers are likely to care about. The spec revision basically makes a number of things that are optional in DX10 compulsory under the new standard - such as 32-bit floating point filtering, as opposed to the 16-bit current. 4xAA is a compulsory standard to support in 10.1, whereas graphics vendors can pick and choose their anti-aliasing support currently.
We suspect that the spec is likely to be ill-received. Not only does it require brand new hardware, immediately creating a minuscule sub-set of DX10 owners, but it also requires Vista SP1, and also requires developer implementation.
With developers struggling to justify including DX10 features in their games (see the recent comments by John Carmack and Mark Rein), they're going to be about as likely to further limit their product's market as they are to start developing NES games again. This is especially true given the incredibly limited benefits 10.1 is bringing to the party.