iOS 8 is due to be released sometime today (Wednesday, Sept 17), so jailbreakers should avoid updating until a new jailbreak is released.
If you feel the need to update anyway, remember that it will be a one-way trip to iOS 8, and there might not be a jailbreak available for iOS 8 for a long time. You will not be able to downgrade or restore to iOS 7 after upgrading to iOS 8.
Also, this is probably the last day you can restore to iOS 7.1.2 if needed. Apple usually closes the update window for the old iOS version very soon after releasing the new version (within hours).
Keep in mind that you cannot update a jailbroken device to iOS 8 via OTA (Over The Air). Instead, you will need to use iTunes and click “Restore” (for jailbroken devices, it’s not a good idea to click “Update” because you’ll lose some disk space until the next time you click “Restore”). Make sure to backup your data (to iCloud or using iTunes) before restoring.
For news on future new jailbreaks, you can follow well-known jailbreakers such as @evad3rs, @panguteam, and @musclenerd. Please be careful to avoid scams selling fake iOS 8 jailbreaks or pretending to offer them in exchange for surveys – only use jailbreaks that are recommended or endorsed by well-known jailbreakers. You can check this partial list of scam sites for examples of scams.Mark Bruce & Kory Lee