Real-estate postering aside, this deal does not "a rebounding real estate market..." It is no coincidence that Google's East Coast offices are located in this specific building. The building happens to be a major internet peering point for the entire NYC region. So no, I do not see a major rush to buy entire city block sized buildings unless there are other enormous, industrial grade, internet peering hubs floating around NYC. (
http://www.nytimes.com/2008/10/01/business/smallbusiness/01h...)
Also, the NYC tech scene is on fire, http://news.ycombinator.com/item?id=1957538.