0.6.1 can be easily upgraded to 0.6.2.
SSH into your pi, login with root, pass = raspberry. Then execute this command
wget
http://xbianmirror.8s.nl/xbian/Patches/XBian0.6.1to0.6.2.sh && chmod +x XBian0.6.1to0.6.2.sh && ./XBian0.6.1to0.6.2.sh
Good luck with it! Please post back your results!