What became of Ihaka & Temple Lang's (2008) "Back to the Future"?

Ross Ihaka and Duncan Temple Lang’s 2008 conference paper [1] (PDF) came to my attention via About Lisp-Stat | Lisp-Stat, and I wonder what happened leading to the (apparent?) abandonment of this idea. Does anybody know?

1. Ihaka R, Temple Lang D. Back to the Future: Lisp as a Base for a Statistical Computing System. In: Brito P, ed. COMPSTAT 2008. Physica-Verlag HD; 2008:21-33. doi:10.1007/978-3-7908-2084-3_2