[britta]

For an example of what Substrate can do, saurik also released Winterboard for Android today (https://play.google.com/store/apps/details?id=com.saurik.win...):

> WinterBoard is a "theme engine" that allows you to use the numerous themes you may find in the Google Play Store on your device without having to install custom ROMs or use custom launchers. It allows you to use almost any launcher icon theme with your stock launcher and supports "Theme Chooser" themes without CyanogenMod.

Winterboard is for customizing graphics with more flexibility; it's not messing with how apps work.

You could also imagine people developing a collection of Substrate extensions that each implement a specific launcher customization, so that you can build up your desired set of customizations one-by-one instead of trying to choose between several launchers that each have parts of what you want.