This /purposely-unreleased/ version of Cydia has only one major change in it (and four tiny things, only one of which is user-visible: the keyboard thing under Search): a modification to “stashing” (the step where your filesystem is rearranged during the initial jailbreak process) made for comex, who recently has been talking about his new platform for handling these things.

This change has not been tested on devices that are already jailbroken (well, I did a cursory test for 2 minutes, but that was all), and users upgrading to this version of Cydia do so at their own peril: Cydia might end up in a “permanent re-stash” loop, or force a stash when the user has purposely previously tricked the mechanism not to (leading to a corrupted filesystem).