Just adding to this: it may seem as though unless you're using 11-specific features you'd be as well off with 10, but that's not really the case.
All D3D10 class hardware is capable of supporting D3D11 (with at least D3D_FEATURE_LEVEL_10_0), so there's actually no valid reason to prefer 10. By using 11 from the outset you are better positioned to move up to 11 in the future, or to drop in 11-level features for higher quality rendering modes, and with minimal code disruption.
...Gah?
Never seen mention of this anywhere for the past month+ I've working on this. Either my reading comprehension is seriously lacking or such an elementary fact is practically hidden. Anyway, now I finally know why I kept finding D3D9 and D3D11 tutorials and almost none for D3D10....
Thank you, and I'll make the switch to D3D11 right away. Btw, the differences seem to be:
1) As mentioned, the introduction of the device.Context.
2) No more effects, need to compile Vertex, Pixel etc.. shaders separately. And thus instead of effectvariables I need to use constant buffers.
3) No D3D10 font/Sprite. Don't care, using my own classes already.
And, finally, If I want D3D10 harware to run my game, I just need to make sure I respect these limits: http://msdn.microsoft.com/en-us/library/bb509540.aspx
I think that's about it...