I saw the announcement back in early 2012 when the first collaborative editing project was announced, and was hoped to be taken on during the summer of code that year. After LibreOffice 4 came out, I had hoped that maybe some of that code had been implemented but sadly no. I went to go look at the git branch which included the basic telepathy integration but the branch has been removed. Is there anywhere that this is still being worked on? Is there a branch of LibreOffice 4 that has implemented the basics that were developed back then?
AFAIK there’s been no further progress. Are you interested in doing some work on this branch?