I just bought an i5 this past Friday (2/12) at the Apple Store in Lancaster, PA. I was hesitant because it was a week 48. After getting it home, I was happy to see no yellowing, flickering, loud hard drive, or buzz when brightness is turned down. I found it quite strange though, that after trying to apply the 2 screen flickering updates from Apple, the updates told me this computer does not need the update.
I double checked the box to make sure it was not opened and then resealed.
One thing is for sure, it's a beast and I'm loving it.