Pangu released a new jailbreak for ios 8/8.1 today. But it has some issues so please hold off until they get worked out:

Issues so far:
1) Occasional locks on apple logo on boot
2) SMS sending of images broken
3) Cydia not installed, have to use ssh to install manually.

The jailbreak will get sorted out over the next few days and we will post an update when it’s good to go.

Also, like all major updates, tweaks will need to be rewritten to support ios8. The current developers have not had time with ios8 to do this yet so even when the jailbreak is stable, you may want to hold off for a couple weeks.