It's a change to the managers's profile page where previously you could see a managers' awards. You will now also be able to see what trophies they have won or come runners up in during their time as manager.
The attached screen shot from William Hsu's page shows his achievements with his 2 teams. You may also notice an addition at the top where it says how many weeks he has been in charge of the teams.
Some of the long term managers (who joined before March 2010) may have this a little faulty for their primary team as I didn't store exact game week numbers for managers joining clubs until then. I just have a date and have attempted to guess the game week number from that. If any managers know this is wrong I will be able to correct it providing you can remember the game you first managed a team for. You just need to let me know.
If not, I don't think it will be that big an issue as it will only be a few weeks out and can't include that many achievements that aren't yours. As stated though, I could always correct it if you let me know.
To any managers reading this, I'm not bothered if this is mentioned on the message board now. May be fun for you to talk about it and confuse managers who won't know how you know it is coming!