The new driver doesn't change anything.
The nouveau people are working on a solution, It seems as if the edid infos on the newer sony vaios need to be obtained from the systembios, that needs a kernel patch, because it doesn't provide such funcionality.
Maybe someone could test this kernel here: https://bugzilla.redhat.com/show_bug.cgi?id=536923
And what about the brightness issue? Where is the right place to report this? Think that it is not the nvidia drivers work, more an acpi issue?