I have a Riva128 video card (4MB) which is correctly detected by the installer. However, it configures the 3.3.6 SVGA server instead of using the 4.0 nv_drv.o module. If I run Xconfigurator, it also claims that there is no 4.0 module available.
This defect is considered MUST-FIX for Winston Beta-5
This defect has been re-classified as MUST-FIX for Winston Gold-release
The problem is still present in Xconfigurator from pinstripe (does not show an XFree86 4.0 driver as being available).
This was added July 28th (not as default - we prefer the "no surprices" way.