First off, the Nova Launcher pretty much looks like the stock Android 4.0 home screen, so it won't alter the purity of the visual experience we know you are so fond of on your brand spanking new Galaxy Nexus. Second, it is supposed to work on any ICS device you throw at it, although the list of those is pretty short at the moment.
Third, and most important, it adds a lot of added functionality to your home screens. The icons at the bottom dock are now able to be swept left and right, allowing you to fit shortcuts to much more of your most used apps there, and access them from anywhere.
You can also adjust the grid and widget sizes, to mix and match for the perfect ratio of screen real estate/crammed functionality. Last, but not least, you can change the way of choosing widgets for the home screen away from the default one, which some people scoff at. Here is the full list of features, and more are said to be on the way:
- Scrollable Dock
- User setting for auto-rotate
- Resize any widget
- All/New/Downloaded categories in App Drawer
- Widgets-in-drawer (requires install as a system app) or from system picker
- Shortcut or resizable information in Widget Drawer
- Edit App Shortcut icon and label (Supports ADW Icon Packs)
- Wallpaper scrolling options (Disabling scrolling improves performance of live wallpapers)
- Cube desktop effect
- Various other smaller tweaks/optimizations
You can hit the source link and take it for a spin, but beware it is Android ICS-only. Gingerbread handsets have a number of other launchers to choose from at Android Market, so don't hate on the Nova Launcher developers.