If you ask me what types of data should be made available on the open government portal, we could be here for a long time. I would probably say it should be the opposite: What data should not be there? I think there is a good case to be made for limiting the information that's not publicly available to what's commercially sensitive, cabinet confidences or solicitor-client privilege, but it should be open by default. I think that would relieve a lot of the pressure that's put on access to information shops in the government and it would simplify many people's lives.
So what type of data? I think it should be the vast majority of data held by government departments and institutions.