You might want to skip the iOS 9.0.2 update right now if you're dependant on your phone or tablet for schoolwork or a big project at your job. If you need your device and apps to be fully functional today, tomorrow or the next day, you might want to hold back.
If you haven't updated your apps in awhile and you're moving from iOS 8 to iOS 9.0.2, there's a chance some of them could start acting up. (You'll also get signed out so that could be a problem if you don't have your login info handy). Same goes for iOS 9.0/iOS 9.0.1 to iOS 9.0.2 but the odds aren't as good.
We've been seeing issues with apps on iOS 9 and others have too. There's a good chance iOS 9.0.2 won't cooperate with some applications and maybe, just maybe, your core apps will be affected.
The last thing you want is for files or an app to start acting up right before a presentation at work or school. You'll want to dig into app reviews and check in with your IT department before you install the iOS 9.0.2 update.
iOS 9.0.2 isn't going anywhere so take your time.