So updating comes with a cost and if your planning on upgrading to the new IOS along with getting a new iPhone 6 or 6Plus then you will more than likely be out of a jailbreak for 6 months to a year. Jailbreak Devs have a harder time making new exploits for the new iPhones because they have dew A chips in them. a jailbreak for ios 8 for a iphone 5, 5s may be sooner then a jailbreak for iphone 6.

ios 8 comes with some special things like quick reply for messages but over all if you are on iphone 5 or 5s i would stick with ios7, unless you are experiencing some problems with the firmware.
Me specially, well im going to buy myself the new I6+ and ill probably try and keep my old I5 for a back up, and keep it jailbroken on ios 7.1.2, until they come out with a jailbreak for ios8

You can expect a Jailbreak for ios8 alot sooner than 6 months to a year..

iOS 8 isn't that great. I have been on the Dev beta since day 1 and I personally don't think it is that good.

You will definitely lose it, and if your jailbreak is running alright I would not. And like everyone else has said itll be atleast 6 months and possibly longer if you have the new phone.

eels wrote You can expect a Jailbreak for ios8 alot sooner than 6 months to a year..

I meant a jailbreak for the iphone 6 it will take much longer for a release because its a new phone

Eventually there will be a jailbreak. It could take awhile. But that is the risk you are taking when you do upgrade your device.

there could be a jailbreak for ios 8 in the future but i would stay with my jailbreak untill an official jailbreak is released

Hm.. why ios 8 exactly? You just get a few new nifty things that you get.

There was some reports when the IOS7 jailbreak came out that they had found a new exploit and were saving it specifically for the new iPhone and iOS8. So it wouldn't be 6 months, but closer to 2 months if those reports were true, so the new iPad would be included also.