This is not news. It's called PAE and is a feature that has been included in windows for a long time. You can enable it by modifying the Windows boot parameters, but there is still a hardcoded 4GB limit even with PAE enabled, and drivers most likely will not all support it and you will get BSODs and things won't work properly. That's why 64-bit Windows needs x64 specific drivers.
As for what the link says about 32-bit Windows not letting you use the whole 4GB of ram, the address space is not only used by the graphics card, it's also used for address registers and other PCI(e) cards, if I remember correctly. The patch disables the hardcoded limit, which might seem like it works at first, but will almost guaranteed cause driver related issues. As the address space for RAM is normally only 4 bytes, addressing memory will not work correctly for drivers that are not coded so they know how to react to longer addresses (either on purpose or by luck). It works correctly for most applications, because they use process-specific address space, and so they don't refer to memory by absolute locations, but rather relative to the start of the process memory.
Of course, someone may be lucky and their drivers might all be PAE-compatible, however, PCs use a lot of drivers, and the more PCI(e)-cards or USB devices you have, the higher the chance some of your drivers don't support PAE. For this reason, I haven't tried to mess around with it and have rather just used x64 Windows and x64 drivers to ensure my system doesn't become unstable (at least not if it's avoidable). I'm assuming that Windows' built in drivers all support PAE, so if you don't use any USB devices that need to install drivers (either from windows update or disc), and you haven't installed any PCI(e) cards, the graphics card drivers should be the only thing that could fail, making it worth a shot to try if you have 4+ GB ram and 32-bit Windows.