It is possible on the FTDNA website to discover whether a particular haplotree section has a Project associated with it. I found that my new group did indeed have such a project and that it is called the 'South Irish Project'. This is the first time it has been suggested that from DNA evidence our name has distant origins in the South of Ireland, though perhaps we shouldn't be surprised in the light of the paper trail which has taken us to Lismore in County Waterford - see my blogs of 2009, Feb 3,8,13; 2010 Nov 13; and 2011, May 25, Oct 23, and Dec 3,4.
The R-L21 South Irish Project has many surnames associated with it, including O'Sullivan and McCarthy to which I have referred in our paper trail - see blogs on 2009, Feb 8; 2012, Nov 13, and 2011 Jan 9. I have been in touch with the Project administrator and as and when I hear anything of interest I will let you know.