Apple has already released iOS 8 beta 1, and those who update to it past iOS 7.0.6 will not be able to jailbreak. The beta is available to registered developers only, but many people have it on their device now.
Now is it worth to give up the jailbreak for this update?
If you have a single iOS device
Beta software is unstable, so do not install iOS 8 beta if you have one iOS device. Many developers have updated to this beta but they are not able to access all the features including widgets and third-party keyboards.
Also, remember that several features in iOS 8 are already supplied by Cydia. Jailbreak developers have always brought new varieties so it won’t be wise to update to iOS 8. Once the new label wears off, you would want to downgrade again to a jailbreakable firmware, and only you can downgrade till iOS 7.1.1, for which no untethered jailbreak is available. Our advice is to stay away from the update.
If you own more than one iOS device
If you own 2 or more iOS devices, you can of course test iOS 8 beta on one of them. For example, if you have an iPhone 5s and iPhone 5c, you can use the 5c to checkout the new features in iOS 8, while still enjoying the jailbreak on 5s.
But remember the beta version will take away your favourite tweaks, and in case there is no jailbreak released for iOS 7.1.x, you’ll have to wait till an iOS 8 untethered jailbreak is released, which would not happen at this point.
The ultimate decision is yours. Just make sure to weigh in benefits and cons, instead of getting all hyped up about the new firmware.