BlackGeek is the developer of GeekSnOw tool, who has tested the PanGu jailbreak on iOS 8 Beta. A few days ago on Twitter, @BlackGeek posted a photo of PanGu running iOS 8 on Beta. GeekSnOw is an iOS 7.1.1 tethered jailbreak program built on @Geohot's limera1n exploit and @winocm's opensnOw project. BlackGeek formally announced today that he plans to release the GeekSnOw untethered jailbeak for iOS 8 Beta in the very near future, and this will be compatible with the existing iOS 8 Beta 1 and Beta 2.
BlackGeek has named this iOS jailbreak as 'PanGu Unofficial' on the GeekSnOw page, being the author's disclaimer:
I’m not affiliated with PanGu official team! My PanGu-Unofficial tool isn’t copied from the original one. I just use the same exploit (from @i0n1c) and bundled modified PanGu’s resources to my unofficial version. The main credits for this jailbreak goes to PanGu official team. I just ported binaries in order to add support to iOS 8 beta.
This means that, in order to avoid wasting vulnerabilities in iOS 8 Beta, BlackGeek will use an exploit which has been exposed by PanGu.
It's noted that BlackGeek has not provided an ETA on this, and on his website he's issued two requests: the authorization from the PanGu team to release the unofficial version, and a public technical write-up of the original PanGu tool.
It's not absolutely necessary that we have this unofficial jailbreak, but at least there's hope of an iOS 8 public jailbreak in the future. It's also claimed by the PanGu developers that they have retained some unpublished vulnerabilities for jailbreaking the iOS 8.