Anything Directx11 does for me that DX10 doesn't?

Really, what kind of effects do i expect?

And, is there a way to somehow make your DX10 GPU into an DX11 one? I hate that the GPU is stuck with the DX standard it is shipped with, any idea about this?

The only real feature I see is Tesselation, and I have some serious questions about performance loss when used. More realistic textures (faces are a good example), but I don't see anything really revolutionary at this stage.

And no, a DX10 GPU can not do DX11 features. Yes, I know ATI cards already have a Tesselation unit, but M$ has made it clear in the DX spec: You support all of the features for a given DX level, or you don't support it at all. (Hence, why NVIDIA forced what became DX10.1/DX11 to be dropped from DX10, as they didn't have any capable hardware at the time).