When first writing this review I had seen only a preview version which is close but not identical to the final version, but the final version is now available for download from Kaspersky's UK web site (existing registered users only). For new users, you will need either to buy a retail pack or buy the license on-line.
There are a number of changes; it is much faster to install than ever before and there is a small change to the on-screen gadget - that is just about all there is to see until you start to use it in earnest. A new addition, Safe Money, adds a secure browser with Kasperky's own virtual keyboard that provides a safe means to access a bank account and should be enabled if you want that facility, and appears only after a reboot. You will not be asked to input the license data until after the reboot. Once fully installed, I would suggest that you update its definition and database files.
Although Kaspersky's anti-virus engine (a version of which is used in all of its products) is not known as one excessively prone to either false negatives or positives, it will sometimes do so. In some instances, KIS 12 could report an item as infected some way today, refer it to base for further and more extensive testing, and then declare it safe again in a couple of days. For the user who may have quarantined that file, it can then be restored in the full knowledge that there will not be a recurrence. I cannot yet say that the new version will never do that, but Kaspersky claim to have significantly beefed up the engine to reduce the number of false reports. That has to be a real and beneficial improvement.
As the preview was not fully functional I was limited to what other checks I could make but there are several claimed small improvements and some new features which should add to the user experience. As one of the best and most universally trusted products of its type, and it has been for many years, any small improvements are to be welcomed.
I did find one issue and that is one I cannot currently explain with total certainty. In the past and with prior versions, any unused licensed time remaining on an existing product can be transferred to a new one simply upon its installation, regardless of the version for which that license was issued (within the same product line only). Once that existing license expires, you can then add the license supplied with the product and thus gain full advantage from whatever improvements that version provides provides. However, on this occasion, and with almost the entire license period of KIS 2012 remaining in place (admittedly with a previously unused stockpiled 2009 license), KIS 2013 would not accept that license and insisted on a fresh one. This may be a change of policy by Kaspersky but they have been rather lenient in the past and may now wish to tighten up on such issues. I now believe that to be close to reality and that my license, although valid for 2012, was not acceptable to 2013 - 2012 licenses will be fine!