According to greenpoison and redsnow on twitter, an untethered jailbreak will be released from Pod2g soon for iPad 2 and iPhone 4S on 5.1.
But iPad owners, do not update yet! We do not know the exact release date yet, we just know it will be in the near future.
As always, keep a backup of your tweaks and stuff with a backup app like PKGBackup, so the update process will be easier.
Now, we wait and let Pod2g work his magic. :)