the rpitc2 seems not implemented with vcgencmd command
to enable this:
apt-get install ca-certificates git-core binutils
apt-get update
apt-get install binutils
wget https://raw.github.com/Hexxeh/rpi-update/master/rpi-update
cp rpi-update /usr/local/bin/
chmod +x /usr/local/bin/rpi-updat
rpi-update
reboot
then run:
sudo /opt/vc/bin/vcgencmd measure_temp