Long live to openvswtich-brcomptt

Now that openvswitch-brcompat is not officially supported with recent kernels (Ubuntu 12.10 with kernel 3.5), the alternative to configure the bridges directly in the interfaces file has change a bit... but is still pretty forward!
Simple case with 1 bridge and 1 attached interface:

allow-ovs br99
iface br99 inet dhcp
    ovs_type OVSBridge
    ovs_ports eth0
allow-br99 eth0
iface eth0 inet manual
    ovs_bridge br0
    ovs_type OVSPort

And to bring it up and down:

ifup --allow=ovs $list_of_bridges
ifdown --allow=ovs $list_of_bridges

Et voilà! 

More info at:  openvswitch-switch.README.Debian