Sources within Apple are particularly enthusiastic about a new security system called Rootless, which is being described internally as a “huge,” kernel-level feature for both OS X and iOS. To prevent malware, increase the safety of extensions, and preserve the security of sensitive data, Rootless will prevent even administrative-level users from being able to access certain protected files on Apple devices. Sources say that Rootless will be a heavy blow to the jailbreak community on iOS, though it can supposedly be disabled on OS X. Even with this Rootless feature coming to OS X, sources say that the standard Finder-based file system is not going away this year.
Apple has been busy closing vulnerabilities used to jailbreak with each of the last three iOS updates blocking exploits used to jailbreak.
As of yet, a public jailbreak of iOS 8.3 has not been released (although one of iOS 8.4 beta has been demonstrated) and we've yet to see a jailbreak surface for the new Apple Watch.
For more details on the 'Rootless' security system and how it could affect the future of jailbreaking, please follow iClarified on Twitter, Facebook, Google+, or RSS for updates.