Google Voice has been updated to version 0.2.0.2 and as per the usual Google updates, there is no change log. It would be fun to talk about even minor performance improvements but nothing is certain. Feel free to download the latest update and let us know if you find anything.
UPDATE from Google Voice Blog: The Google Voice update features “direct access numbers” which lets users place calls much faster. Until this update, the Google Voice app had to make a request to the Google Voice server which added some lag to the service. With Direct Access Numbers, users have a unique phone number assigned to them for every person you call. This means you no longer have to access the server each time you make a call and the whole process is faster.
Download Google Voice from m.google.com/voice.