What I would really love to see is something similar to CM7's Theme Manager. People make themes, you download, go to Theme Manager and choose which Theme you're interested in, hit Apply, reboot. Ta da! All done. None of that wipe cache, flash this and that, etc.
Now... what is my point? Something like Code Themer. If we have the ability to write codes and add stuff to it, like power control to the Notification bar, we'd write it, test it, and apply it like it was a Theme. Only thing I wouldn't do, is sell the codes and stuff. That may not sit well with the developer(s). This would be just an option (feature) that comes with the ROM as a do-it-yourself thing. We could contribute the codes to the developers, get credit for it and whatever. This would also make it a lot easier on some people who have a hard time trying to find and pinpoint what they like to change or add to it. So, in the Code Themer, it would have a whole category of different sections of what makes up the ROM, select one folder (Status bar/Notification bar for instance), it'll provide you everything that makes it function and show what all it contains so you can easily pick out what you want to edit, change png's out of, xml, etc. You get the idea.
I would kill for an option like this. I have a hard enough time finding different things and worry about that I may have missed an area to edit so my theme project is complete. It makes me wonder if I edit something like... Phone.apk. Do I need to also edit parts of that somewhere else too? Who knows. But simplicity from this idea would bring customizing ROMs, Themes, and such to an entirely new and different level.
