As you may know, Bumblebee 3.2 was released. It has improved support on Ubuntu 13.04 with Primus.
Bumblebee is an open-source project for the management of Nvidia Optimus on Linux.
Bumblebee 3.2 brings grealy improvements for the energy consumption of your system, that increases the autonomy of your Laptop.
It also improves support for Dell Vostro 360 and for the new Lenovo laptops.
To install Bumblebee 3.2 on Ubuntu 13.04 Raring Ringtail, do this:
Add the PPA:
$ sudo add-apt-repository ppa:bumblebee/stable
Update the repo index:
$ sudo apt-get update
$ sudo apt-get install bumblebee bumblebee-nvidia