I have a 27" i7, 8Gb memory. I have had the machine for @ 8 days and had experienced the tear/flickering after 2 days. I was advised to do the PRAM reset which seemed to stop it.
Last night I applied the firmware update successfully. Today, I spent the morning working in iPhoto.
I CAN CONFIRM AT THE FIRMWARE DOES NOT CURE THE FLICKERING
While I am sitting here typing the screen is flickering every 20-30 seconds. It varies from the odd flicker in an area of the screen to the whole screen flickering. I can also confirm that I have just has the screen tear 10 cm from the top of the screen, icons have shifted to the top of the screen.
I took a screen shot - but that seems to not be effected by the graphics problem. I will see if it happens again and post a picture with the system profiler showing with the ROM version
Update 1
I have taken a picture of the screen with the "tear" corruption - also with the profile settings showing the upgraded Graphic rom in the picture:
Last night I applied the firmware update successfully. Today, I spent the morning working in iPhoto.
I CAN CONFIRM AT THE FIRMWARE DOES NOT CURE THE FLICKERING
While I am sitting here typing the screen is flickering every 20-30 seconds. It varies from the odd flicker in an area of the screen to the whole screen flickering. I can also confirm that I have just has the screen tear 10 cm from the top of the screen, icons have shifted to the top of the screen.
I took a screen shot - but that seems to not be effected by the graphics problem. I will see if it happens again and post a picture with the system profiler showing with the ROM version
Update 1
I have taken a picture of the screen with the "tear" corruption - also with the profile settings showing the upgraded Graphic rom in the picture:

