Although the KMS video drivers have improved a lot, there are still a lot of nVidia adapters for which nouveau fails to provide any useful graphics screens. For new users, the failure to boot to a meaningful display is frustrating. The problem used to affect only persons that had implemented the proprietary closed-source drivers, and their graphics failed when the kernel changed. They could be warned in advance because a lot of them came to the forums for help in getting the propriety driver installed. With KMS, people are having trouble with their initial look at an openSUSE version. I expect many decide that openSUSE is flawed and move on to other distros.
I propose two fixes/workarounds:
(1) Make the GRUB option "nomodeset" be the default for all installation media. There will be very little impact on the NET install CD or the DVD install disks. The lower graphics performance for the Live CDs will be a small penalty to pay for the benefit of getting a great many more systems to boot. If the "nomodeset" appears after the "VGA=" on the GRUB options line, it will be easy to advise people to try removing it when booting. They will quickly learn if they need it or not.
(2) In the installation process for GRUB, detect the presence of an nVidia adapter and pop-up a screen advising the user that the installed system may need the nomodeset option in order to boot. I single out nVidia because nouveau seems to handle many fewer models than the KMS drivers for the others. I don't have any ATI adapters, and the one i915 system I have boots without trouble. One of my nVidia-equipped systems boots to a blank screen with nouveau, and the other corrupts the alternate terminals.
I have no doubt that the KMS developers will have drivers that handle nearly all adapters in the near future. As someone having experience with reverse engineering, I'm really impressed with the progress, but kernels 3.0 and 3.1 still need some work. As we can help our users get a more satisfactory experience with quite small changes, I think we should do so.