LibreOffice has successfully replace OpenOffice.org only two years since it's being forked out of Oracle's OpenOffice.org. People liked to contribute to this project instead of going back to the original code of OpenOffice.org which is now handled to Apache project.
Several people have a better idea of how to make improvements to LibreOffice by introducing collaborative editing features like what we already have in Google Docs. Basically it enables two or more people to work on a same documents together. It's very usefull features when you are entering an enterprise market since a document may be worked out by many people and it's so ineffective if you have to stop working on it to let other people edit your work.
This new feature will not come in short, but it will be added as one of the idea for GSoC this year. Students who are interested on implementing this feature should contact LibreOffice developers to talk about this.
It uses Telepathy, a flexible, modular communications framework that enables real-time communication via pluggable protocol backends. It has been used in many applications, such as Google Talk, MSN, Yahoo/AIM, IRC, and many other.
Here's a short video demonstrating how LibreOffice can be used to work in collaboration with other people over the Internet: