The documentation for FamilySearch.org's Family Tree program discusses the imminent introduction of a true merge function. However, that particular feature is not yet available as of the date of this post. What that means is that I can do nothing with my ancestral lines further back than about 3 generations. Past that point, there are unresolvable duplicates in the file that totally prevent me from making any further progress in sorting out the data ported over from New.FamilySearch.org.
In New.FamilySearch.org, there was an artificial limit on the number of individual records that could be combined for any one person. However, in the case of my ancestors, the limit was way too low and there are many uncombined copies of the same individuals that cannot be combined due to the fact that the total number of duplicates exceeds the arbitrary limit. So now I have unresolved duplicate pedigrees, as well as individuals in Family Tree. So, by the time I get to my Great-great-grandfather Sidney Tanner, for example, I cannot begin to untangle the duplicates and problems without the merge function.
There is also some controversy over whether or not Family Tree will allows users to add individuals to the file directly in Family Tree. Two days ago, I was in the new FamilySearch Center in Nauvoo, Illinois and one of the missionaries there showed me how he had been adding names to his file. Until I can get a handle on the merges, I have no one to add to the file, so I cannot duplicate what he was doing. I am getting mixed messages as to whether or not adding individuals is yet possible.