I've posted it as camera_umd/uvc_stereo in git://ram.umd.edu/umd-ros-pkg.git.
It still needs some changes to the underlying driver to make synchronization
work properly, but it should get close as it is. If your cameras don't have
big exposure-related shutter-speed changes like mine sometimes do (taking
them out of sync), it will broadcast synchronized pairs well.

uvc_stereo broadcasts matched pairs of images:
  * to /{left,right}/{image_raw,camera_info}
  * using camera_info_manager and uvc_cam's driver
  * with support for rotated (180 degrees) cameras

It doesn't yet support:
  * reading or broadcasting JPEG streams from the cameras
  * working in anything but RGB8
  * setting camera parameters by dynamic_reconfigure or message streams

Docs soon at http://www.ros.org/wiki/uvc_stereo

 - Ken