I used to install it on XP as it needed it, even when I installed SP2, I would have errors with certain on board components. (I have not tried SP3 as I have never run it on physical hardware, only in VM's which obviously didnt need it)
In Vista RTM, My first experience was that I plugged in a USB drive to copy my drivers and it copied at about 9MB/s which I thought was fast... Installed the drivers, then tried again and the speed went up to 23MB/s!
On Vista SP1, I got the high USB speeds out of the box and when I installed the drivers, it just went next > finish really quick and did not seem to install anything, so I guess the drivers were bootstrapped.
I am currently using Windows 7 7048 and out of the box it did not require any drivers and I have been getting good speeds on USB and performance elsewhere. When I reinstalled 7, I did install the drivers again but it did the same as on Vista SP1 and just finished without visually doing anything, so I guess 7 contains the latest drivers.
It may be possible that in the future, there is some upgrade that does many new features, but I am sure we will all hear about it first. If everything is working and you get no yellow triangles in computer management, I think you are safe!