This morning AncestryDNA announced some major updates to its available services. DNA Circles is the name for what was previously known as DNA match groups. This is being launched in beta as the technology is still in its early days. The help section of DNA Circles has lots of information on how this works and the company also will be posting an overview for everyone to read shortly.
You need to have a subscription (any level) and a public tree linked to your DNA results in order to see your own DNA Circles. You will be able to download your old DNA matches for a limited time.
You can read more in the Ancestry Blog at http://blogs.ancestry.com/ancestry/2014/11/19/dna-matching-just-got-better/.
Here are some screen shots to illustrate the new DNA features. Click on any of the following to view larger versions: