Apparently it is discontinued, and google are going to sell through old stock then its done. No mention of if a Nexus 2 is likely though:
http://au.gear.ign.com/articles/110/1106992p1.html
http://www.huffingtonpost.com/2010/07/19/nexus-one-dead-google-dis_n_650855.html
So lets hope more handsets officially get froyo soon then!