My wife's 21.5" iMac Core2duo 3.06 ghz with nVidia GeForce 9400:
Before:
After:
Not impressive right? HOWEVER, her machine was previously reaching Geekbench numbers of 4606 and after the update it hit 4720.
I'm not even sure why since the update was graphically related and that benchmarker doesn't really apply to graphics.
Now, the numbers I was getting with my Corei7 iMac 27" 2.8 ghz model prior to the update:
(Disclaimer: this was the numbers I was getting before I prematurely applied the driver in the updates for the Summer 2010 refresh
machines to my machines.
After todays update:
My geekbench numbers are now: 10061.
The after listed above is also consistent with the benches I was getting when I applied the ATI 4850 HD driver that was inside the Summer 2010 refresh Mac updates using Pacifist - they're virtually identical so we can presume the drivers in the Summer 2010 refresh update is indentical.