I know for me the greatest aspect of DX11 will be the incorporation of GPGPU capabilities.  I'm currently using CUDA, and while performance is fantastic, the api is a little akward.  Though I expect that dx11 gpgpu performance won't come near native CUDA on release.
I'm also on Vista, but really only went that way as I needed 64-bit for 8GB ram, and XP-64 support was disgraceful at best. Never had a moment's hassle with it (well apart from Creative drivers which were improved one month after I installed).
Hell, the o/s even detected my highpoint raid card and applied the correct drivers automatically.
	
		
			
		
		
	
				
			I'm also on Vista, but really only went that way as I needed 64-bit for 8GB ram, and XP-64 support was disgraceful at best. Never had a moment's hassle with it (well apart from Creative drivers which were improved one month after I installed).
Hell, the o/s even detected my highpoint raid card and applied the correct drivers automatically.
 
	 
  
 
		 
 
		