I do not think patents which are blocking your ability to use the DLLs in Wine. It is your Windows license.
I believe that if you have a Windows license for your machine, you are free to use Windows or its DLLs. This includes all the "free" downloads from their web-pages. I think, if you do not have a license for that machine, you are in violation of the license, which is illegal.
I am not sure i got all the details right but you can probably find more on their web-page.
If i understand it correctly, it of course means that there are no really free downloads on their web-page, as they all rely on a purchase of Windows. This makes the "free" download kind of expensive.
For Wine it means that anything the user has to D/L from their homepage is a no-no.
Oh well, I didn't think about that, sorry. Then it of course is a good thing if we implement our own d3dx.