Jessica Enders has an interesting article at A List Apart on Zebra Striping: Does it Really Help?
Her main points considered are does it increase accuracy, or speed. The raw statistics don't show anything statistically significant. The readers did report a 46% preference for zebra striping, but 36% said they didn't care.
I believe that anything that improves the readability, or visual appeal of information is going to be helpful to users. I also believe that with wider screens and more space between columns, the striping is more helpful. More...