Those who were able to successfully jailbreak their device were met with lots of server errors in Cydia as millions hit the repos to download their favorite tweaks and themes. The issue appears to be limited to iPhones—the iPad actually gains Weather app functionality—and is only affecting some users. But nevertheless, the brilliant evad3rs say they’re on it now…
As saurik points out (Jay Freeman), the big difference with this jailbreak was how the team pointed toward an exact release time, which caused the huge influx of new users launching Cydia. Saurik has been working around the clock to help rearchitect his repository setup, but for now, it seems many of us will simply have to be patient, wait it out and hope the heavy load of users balances out.
Other users are reporting issues with the weather app crashing on iPhone and iPod versions, and appearing on the iPad jailbreaks. The evad3rs team is aware of this, and is working around the clock to help push out an update via Cydia. Please note that you do not need to rejailbreak if you are currently having weather app issues. Simply wait for the dev team to release an update via Cydia, and you can update there once you are prompted.
We've also been seeing some of our users running into devices stuck on "patching kernel" or "Finding Offsets" during the jailbreak. We recommend you wait for as long as you can, but if that fails, hold down home and power to force a reboot (via Pod2g).
Finally, some users have been having devices randomly get stuck on boot at the Apple logo. If this happens, we recommend that you hold home and power for ten seconds and keep trying. Eventually, the device should boot. If that does not work, try holding volume up button if you recently installed a MobileSubstrate tweak.