When an interface is connected in a bridge, no IP is on the interface (you can set an IP in config, but it does nothing).
Virtual machines use bridge very often. The interfaces are in a bridge in host and you can put them IPs in guests.
However, there is a question about IP on the host. You can put an IP on the bridge.
If you really want to delete bride user brtctl command:
brctl delif br0 eth0
brctl delif br0 wlan0
brctl delif br0 vif0
... remove interfaces from the bride br0
brctl delbr br0
... delete the bridge br0
see 'man brctl'
See more: http://wiki.libvirt.org/page/Networking