8.1 patched the expired certificate exploit used for emulators and was also used by Pangu7. AFAIK the PDF vulnerability is not patched yet, but the use of that particular vulnerability is at the developers' discretion. The vulnerability opens up the ability to have an OTA jailbreak like JailbreakMe when exploited correctly, but it's a major security flaw that Evad3rs most likely won't exploit for ethical reasons but Pangu may. Overall, considering how iOS 8.1 ironed out a few bugs that were present on 8.0/8.0.2, it's best to upgrade to 8.1 as any jailbreaks looming in the minds of developers would revolve around 8.1 as it fixes several preexisting issues that detracted from iOS 8.