I don't think its gunna be possible to change the time.. maybe font maybe? ... I have changed the service bars ,lock, little battery on top right and wifi ... my edge Icon is Red now.. so it is possible
we have everything hacked man, the color of your signal strength, the icons, obviously the ringers and carrier logo, battery color, the icon on the slider for unlocking the screen and the one for turning off the phone, the bar where the phone, mail, safari, and ipod icons are, literally everything.
maybe ill get unlazy and post tutorials, but if youve been able to follow the amazing tutorial already posted for how to do custom ringers, you should be able to figure out from there how to change everything else (just look at the extensions for the other files in the different iPhone folders)
well the font of the battery could be changed... however you'd have to find a full set of fonts and save it as a .ttf file and place it in this folder: /System/Library/Fonts/Cache and the problem is figuring out which text file to replace... theres about 30 lol... the most obvious text files are lockclock which i can only assume is the font of the clock as it appears when you are in screen lock mode... that would likely be your easiest first attempt (just use the getfile /System/Library/Fonts/Cache/LockClock.ttf command in iPhoneinterface before you attempt to change it so you can restore your default file if you don't like the outcome)
let me know if you decide to try this out... if someone would be willing to get me a font set that is in a cool font I would be happy to try it out and post my results.