They started to ball rolling on the new HQ in 2010. New exclusive high tech oriented industrial park emphasis on park, lots of green space, lots of big name neighbors.
I've not seen any news on GW2 retention rate problems, other than their periodic bans. Latest was another exploit that let you on average double a very rare and high price crafting ingredient.
My information on GW2's retention rate is all anecdotal, but friends of mine who USED to play stopped playing because everyone burned through the content in about 2 months, leaving only end-game mass PvP battles, mass events, and other things that most of us would call "grindy." And while many of them would keep playing, all of
their friends left because they had burned through the content in 2-3 months, and there was nothing new to explore.
I will grant you, that is a common problem with a new game. However, boxes no longer seem to be flying out the door, and since it's F2P and there are lots of other anecdotal problems (handicapped being banned for using kb helps, getting reinstated, only to be banned again, lather rinse repeat; mass banning because of using an exploit that cropped up due to bad coding, poor customer service) not retaining your base could prove very problematic. Another friend, Owen K.C. Stevens (yes THAT Owen Stevens) told me the other day that friends of his who work at ArenaNet told him the bans are due to a zero tolerance edict handed down by NCSoft that permits no exclusions. Yes, I know that is 3rd hand, but I think the sources are reliable. Read into that what you will.