Here's a rebuttal.
The nvidia drivers offer a number of important features that cannot be found in the free nv driver aside from 3d acceleration, including:
- XvMC acceleration for video playback
- solid multi monitor support, including support for TVs (s-video, composite AND component, interlacing, overscan settings, etc.)
- power management support for laptop GPUs. this is critical, because otherwise the GPU will run at full speed and burn through batteries.
- numerous other features commonly used in laptops such as buttons to enable external displays, brightness control, acpi support, etc.
The list goes on and on.
Finally, I disagree about the comment on linux gaming. I regularly play a large number of non-native games in linux, mostly through emulators like zsnes and sdlmame. Most emulators use opengl for scaling, which isn't offered by the open source nv drivers.
You also attack 2D games, which I disagree entirely with -- there are a very large number of fun 2D games out there. Good graphics alone do not make a game fun.
I agree completely about beryl and the desktop effects, they're slow and look ugly, cause X to crash far too often and are generally useless.
I don't get the part about the "visual enhancements". Contrast, brightness and saturation are usually adjusted at the monitor level. If you mean the digital vibrance and image sharpening effects, those effects are incredibly annoying and I don't know a single person who doesn't abhor them.
Fortunately, the nouveau drivers will soon be able to do all of what the nvidia drivers do aside from play demanding 3d games.
You can help by supplying renouveau dumps if you use the nvidia drivers.
See here: http://people.freedesktop.org/~jpakkane/ren/
So, if you don't need 3d support, don't play games and don't want the desktop effects (they're awful anyways), don't have an nvidia card in your laptop, don't need multi monitor/tv out support or any of the other features of the proprietary nvidia drivers, which most people do not need, stick with the open source drivers. While that list may seem long, most linux users really don't need many of the items on that list.