The ending credits is where memorials are usually put, and Majel will most certainly get one. As to 99% of the audience not knowing who she is, I say bullshit. If she was so obscure, her passing would not have been listed as a "top story" on Yahoo, IMDB, Variety, etc. Virtually every entertainment sites placed the story prominently, and not just those that cater to the genre market. We're talking mainstream media sites, and mainstream news networks, on what was most certainly not a slow news day.
Well to be fair, I am not sure if even 30% of the mainstream public would know who she is. That isn't to say she is unheard of either, but because she was such a phenomenal figure in Star Trek, and being the wife of the creator, it was reported the way it was. I'm all the time seeing people being mentioned who passed away that I have never even heard of (but had some importance somewhere,) and it is a news item to post on those websites afterall.