It is actually Real Estate Opportunities plc that own and plan to develop the site. REO is a london-listed spin off from Treasury although they do still have a majority shareholding.
Latest news was back in November and the chairman said at the time that he expected construction to start in 2010.
I wouldnt hold my breath though. The loans behind the development are going to Nama so I guess they'll have the final call.
Given that there is an abundance of retail on the m50 corridor already and the fact the development includes 600 apartments, it would seem ludicrous to proceed with it at this time IMO.
The site is really an eyesore from the road now mind.