The main new features from Mageia 1 are:
- Kernel 3
- Systemd
- KDE 4.8
- GNOME 3 (currently 3.3, 3.4 is planned for release)
- Many updated browser versions (Firefox, Chromium, Opera)
Sadly, NetworkManager still fails me (fortunately, Mageia includes Mageia Control Center so network configuration is still a breeze, even if there's no connection monitor on Gnome3).
Currently, I'm using the Gnome3 desktop as main environment on this installation and the only complaint I can think of is lack of customization possibilities.