Wine and ReactOS are practically sister-projects at this point that share a ton of code.
ReactOS does replicate the NT Kernel, so in theory (if it ever gets there), ReactOS would be able to run Windows Drivers. IE: the "real" NVidia and AMD Drivers or any other kernel-level drivers that exist in Windows land.
These days, AMD (and even NVidia) have decent Linux drivers. And WiFi drivers have Windows->Linux translators as well. But full compatibility to any Windows binary (including device drivers) is certainly a noble goal. There are a lot of little hardware devices that are written for Windows only (ie: specialized medical equipment, CAM / CNC Mill programs, etc. etc.) ReactOS would allow a smooth transition to Open Source if they achieve their goals.
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EDIT:
It should be noted that there are a ton of Windows OS-level details that Microsoft does much better than Linux too. IE: I'd argue that Microsoft's security model (SIDs + ACLs) is superior to Unix-style Users + Groups. A large group of open-source developers who strongly understand the low-level internals of Windows is certainly a good thing in any case.