Panasonic confirmed to Techradar that there will be no update to the GH2 model this year. It seems that the next Photokina show (that will take place in September, 2012) will be very important event for Panasonic.
Few months ago Panasonic did mentioned that they want to split the Lumix GF line into consumer and professional cameras. A new pro GF camera will probably be released before the GH3.
