Well, for my RHEL6.2 system kernel 3.2 is already one kernel too far. The Intel chipset on my Thinkpad X201 starts flickering once Xorg/Gnome is started. Adding intel_iommu=igfx_off surpresses some kernel messages, but does not fix the screen flickering. Kernel 3.3 makes no difference.
And we're not even 2 years into RHEL6, 8+ years to go :-)