Apple's next shot in the war against jailbreakers is something they call Rootless in iOS 9. Supposedly, this is going to make jailbreaks very difficult, if not impossible.
However, there has been a jailbreak with every major version of iOS and many different ones with minor versions. It's simply a matter of time.
The traditional US jailbreakers gave up around later versions of iOS 7 which is the reason most of the current jailbreaks are now Chinese based.
I do not doubt there will be a jailbreak for iOS 9 at some point. As mentioned, it's a game - a war. Release timing of a JB is critical. Release too soon and Apple will patch the exploits and you then have maybe one point release that is jailbreakable. Release too late and everyone has moved on to the next version of iOS.
So, some assumptions you can make. There will not be an immediate jailbreak release for iOS 9. They will wait until 9.1 or even 9.2. That's because Apple is known to push out a flurry of updates when releasing a new version of iOS. Any one of those minor updates could patch a jailbreak. Also, Apple tends to include fixes, patches and new features with .1 and .2 releases. So you won't see a jailbreak before then. That's tipping their hand to Apple if the JB devs have exploits they are holding.
But once .1 or more hits the talk of a jailbreak will increase and you can pretty much be assured it will happen at that point. Could be six months or more after the initial release of iOS 9.
Historically, that's the way it's worked.
You'll also note that in these forums, historically we will get an influx of people stating they no longer need a jailbreak and that we are all idiots to be waiting for one. Happens every time.
