In a webinar sponsored by Ancestry.com and presented by Tim Crabb of Ancestry.com, there were a few features about the ability of members of The Church of Jesus Christ of Latter-day Saints will enjoy in addition to the present connections in FamilySearch.org's Family Tree. If you have been into the program lately with an LDS Account, you might notice a FamilySearch icon next to the names in your Ancestry.com Family Tree. Here is an example from a screenshot with an arrow showing the link:
Clicking on the icon link, gives you several options. Here is a screenshot of the options:
Presently, the only information which can be transferred between the two programs is that contained in the details section. Sources and relationships are presently noted as coming in the future. From the webinar, Tim indicated that comparing and transferring sources and relationships would come in the next few months. In addition, he mentioned a Star Rating system where the matches between Family Tree and Ancestry.com are rated according to whether or not they match. He also mentioned a "Tree Sharing" function which I did not completely understand.
The last item to come, was the ability to import four additional generations for each end of line in your Ancestry.com family tree from Family Tree on FamilySearch.org. Superficially, this may sound like a good idea but I would only use this if the accuracy of Family Tree were to increase dramatically.
I am assuming we will hear more about these changes in the future since this presentation only had one sentence bullet points for each of these items.