The changes include...
- The Leaderboard (728x90) the ads are now arranged in rows instead of columns,
- A different font, and
- The URL (in green) is on the same line at the Title, whereas before it was on its own line, below the Description.
I don't use any of those creative units, so I can't tell you how overall performance has been effected. Obviously Google is not going to make these changes unless they've demonstrated to themselves it has a positive effect.
However, I've already read from other publishers that their overall revenue has dropped due to fewer clicks. But then again, it's like the "squeaky wheel syndrome", where only the negatively impacted complain, and you never hear from the ones doing well.
Anyways, if you these creative units, post a comment whether it has helped or hurt your overall revenue.