EvasiOn released the first iOS 7 Jailbreak just a few days ago surprising everyone even Saurik who is behind Cydia. This caused several issues for those jailbreaking since many tweaks had not been optimized yet. Now however Cydia has been updated for iOS 7, with amazing changes in the UI making it look much better on the new system.
Saurik states why it was more difficult than normally to finish working on Cydia stating:
Due to evasi0n 7 having been released with an unofficial build of “Cydia”, I had to upgrade Cydia via a package. This is more complex, as packages I release in my repository have to work for all users, not just those on the latest firmware. I have managed to get Cydia 1.1.9 working on iOS 2-7.
Saurik explains that since this update might have been a bit rushed, some issues still need fixing:
Please understand that there are still some things about this build that are “not quite right” (including the dropbar, which I want to have work like the iTunes Store’s song preview bar, but right now is simply broken). I needed to get this out so I could move to Substrate, and thereby kind of hacked that together.
So in other words, most of your basic functionality should work without many issues, but there are still some features and fixes that Saurik wishes to implement in a future Cydia update.
We will need to wait a few days to see which tweaks work and which don’t. Personally I am going to wait a little before updating to iOS 7.