mavros not connected

SITL sim and Gazebo up and running and seem to be working okay, but mavros does not seem to be connected properly (i.e., no ROS messages being published and quick debugging indicates it is not getting anything on the port). I am getting the "bind port 5762 for 2, serial port 2 on TCP port 5762, etc." messages as expected.

Console output excerpt from roslaunch terminal if that helps:

[ INFO] [1454964057.224395989]: FCU URL: tcp://127.0.0.1:5760
[ INFO] [1454964057.225257607]: tcp0: Server address: 127.0.0.1:5760
[ INFO] [1454964057.225686993]: GCS URL: udp://127.0.0.1@127.0.0.1:14550
[ INFO] [1454964057.225944996]: udp1: Bind address: 127.0.0.1:14555
[ INFO] [1454964057.226047410]: udp1: Remote address: 127.0.0.1:14550
[ INFO] [1454964057.283980300]: Plugin 3dr_radio loaded and initialized
[ INFO] [1454964057.284281634]: Plugin actuator_control blacklisted
[ INFO] [1454964057.292492135]: Plugin command loaded and initialized
...etc.
[ INFO] [1454964057.527750830]: Built-in mavlink dialect: ardupilotmega
[ INFO] [1454964057.527810815]: MAVROS started. MY ID [1, 240], TARGET ID [1, 1]
spawn_model script started
[ INFO] [1454964057.689477144]: Finished loading Gazebo ROS API Plugin.
[ INFO] [1454964057.690307101]: waitForService: Service [/gazebo/set_physics_properties] has not been advertised, waiting...
[INFO] [WallTime: 1454964057.730001] [0.000000] Loading model xml from ros parameter
[INFO] [WallTime: 1454964057.736080] [0.000000] Waiting for service /gazebo/spawn_urdf_model
[ INFO] [1454964059.196930778]: Model name: iris
[ INFO] [1454964059.196998256]: Nb motor servos: 4
[ INFO] [1454964059.225054658]: ARI: Services declared !
[ INFO] [1454964059.225144714]: ARI: Binding to listening port from ArduPilot...
[ INFO] [1454964059.225222321]: ARI: SUCCESS in binding to port from ArduPilot
[ INFO] [1454964059.225298208]: ARI: Connecting send port to ArduPilot...
[ INFO] [1454964059.225361665]: ARI: Opened ArduPilot fdm socket
[ INFO] [1454964059.225441463]: ARI: Initialization finished
[ INFO] [1454964059.226095032]: ARI: Starting listening loop for ArduPilot messages
[ INFO] [1454964059.227657767]: ARI: Connected with Ardupilot
[ INFO] [1454964059.228332790]: ARI: Simulation step size is = 0.002500