She was 76 and died at home of leukemia with her son Eugene at her side.
Mrs. Roddenberry is best know for playing nurse Christine Chapel on the original Star Trek series. In addition to that role she played the voice of the computer on every Star Trek series as well as playing Lwaxana Troi on Star Trek: The Next Generation.
Gene Roddenberry died in 1991 and she carried the torch for him since then both in regards to Star Trek as well as being involved in unrelated Sci-Fi shows Andromeda and Earth: Final Conflict.
Majel Barrett-Roddenberry was a stable of the Star Trek universe and she will be missed - we will get to hear her one last time in the new Star Trek movie opening next May.
Source: Mercury News