It turns out the challenge was more about upgrading the project to work with 3.3 than it was upgrading the plug. You can read the Cordova docs, but basically they've changed the way plug-ins work. You now define plug-ins in the config.xml file. In this situation, the ShareImage needed to be placed into this file like this:
param name="android-package" value="org.apache.cordova.ShareImage" /
You can see more about the setup of new 3.3 project on the new branch.