From the Ubuntu Wiki page for GRUB2:
GRUB 2's major improvements over the original GRUB include:
- Scripting support including conditional statements and functions
- Dynamic module loading
- Rescue mode
- Custom Menus
- Themes
- Graphical boot menu support and improved splash capability
- Boot LiveCD ISO images directly from hard drive
- New configuration file structure
- Non-x86 platform support (such as PowerPC)
- Universal support for UUIDs (not just Ubuntu)
Additional information and documentation regarding GRUB2 can be found on the aforementioned wiki page.
