Short version: FamilyTreeDNA.COM cannot presently transfer Ancestry.COM DNA data.
Ancestry.COM recently modified their DNA test. FamilyTreeDNA.COM has previously been able to import the Ancestry.COM data for a $39 fee, but since the modification, has been unable to do so.
I recently contacted their support, who informed me that:
Version 1 of Ancestry's test can still be transferred to FTDNA. They changed what they test for in their Version 2 and that new test is looking at less information than our Family Finder test does. Our engineers are still working to try to make V2 files compatible with our test. Unfortunately, there is no timeframe for when or even if we'll be able to accept those files.
meanwhile, Ancestry.COM promotes:
The new chip, with approximately 700,000 DNA markers, has been designed to help us refine our ability to provide insight into your ethnic and geographic origins and your family’s genetic history. In the four years since we launched AncestryDNA, we have learned that some markers, also known as SNPs, in DNA are better indicators of ethnic and geographic origins than others, so we have created this new chip to focus on those signals and enable further refinements to the results. This will provide further improvements to the ethnicity results we provide. For example, many of the markers that were picked for the new chip were selected because they provide greater insight into non-European populations. In addition, they strengthen our ability to provide matches to cousins who have also taken an AncestryDNA test. Altogether, the changes we have made to the new chip will enable us to provide more of the ethnicity and family story insights you have come to expect from us.
The new chip also includes some markers associated with health. Although we don’t currently offer health or diagnostic products to our customers, DNA data is used to improve our products and develop new ones, and for customers who have explicitly agreed, in external research to further understand human history and improve human health. We continue to explore the possibility of developing health products in the future, and may do so with proper regulatory and legal approval.
The data derived from this new chip is backward compatible with the tests that were done on the prior chip. This means that features like DNA cousin matching will work seamlessly for all our customers. It also means that if you’ve already taken an AncestryDNA test, you don’t need to take a new test for the existing features of our service to continue to work.