I just did a 'check for updates' from the system tray and a few minutes later a message pops up saying I can upgrade to the 2014 version for free. Just follow the link and enter your details, the new serial number will be in your mail.
This only applies to those who purchased the 2013 version during the last sale which was in the 4th week of July I believe.
I got the email too for the free upgrade.
Acronis True Image 2014
just released. Upgrade
now – No charge!