there have been a ton of posts on this already. you can search to find the numerous times it was discussed.
Likely to most benefit the smaller speedy guys and the great route runners.
My best guess is Harrison, Smith, S Moss, Stallworth, Bruce, Holt...just to name a few
I think it will make it even more difficult to guard Randy Moss too.
And to further clarify, there were no actual rule changes. Just enforcing them better. It's a point of emphasis for the referees this year.