There's reports on the Wayland mailing list that for ATI users you can use the Linux 2.6.38 kernel (for the Radeon DRM page-flipping support) and for NVIDIA users if using the Nouveau kernel (the page-flipping isn't yet merged into the mainline kernel, possibly for Linux 2.6.39) and use one external patch, Wayland should now work directly with both of these DRM drivers. This is coming after it's long been a pleasant Wayland experience when using the Intel DRM.
Though if you're using the proprietary AMD Catalyst or NVIDIA Linux drivers, it's still a no-go for Wayland support.
Thanks to EGL DRI2 work going on within Mesa (such as this commit), it's now also possible to use Wayland without Mesa's Gallium3D EGL driver. Instead the DRI2 EGL driver for Mesa can play with Wayland now for the Nouveau driver too rather than just Intel hardware.