I think that publications such as FUMSI, IWR, Research Information, Ariadne, D-Lib, etc are also important. For example, an article about ticTOCs in FUMSI has had over 7,000 views.
There are also various places to post press releases. When I check these, I rarely find information about JISC projects. It’s not enough to simply post a press release on a project website – you have to work at getting it placed, or excerpted, elsewhere.
I’m always happy to post details of JISC projects in the Internet Resources Newsletter (circulation 30,000) but few projects send me details.
I think that the relatively low coverage of JISC projects in the media (apart from, as you say, in some blogs, tweets and conferences) is one reason why some people are not aware of the amount of work, and the outputs of projects, that JISC funds.