This software is largely similar to Chess Openings 2005, which I reviewed last year. Like that product, this one provides a one-stop theoretical reference for opening study. The interesting twist with this version of the program is that it includes not only updated databases, but also has several new features. One of these is the included ICC interface, which is the best of breed GUI for play on the Internet Chess Club (the Chess Assistant Playing interface is also included, but the latter is available via free download). The other is the addition of the Rybka Chess Engine, which I reviewed just recently. The last is very important, because this engine has superior positional judgment, which makes it the best choice for evaluating positions in the opening and early middlegame - where an engine cannot rely so much on raw calculation, and must instead rely on it's evaluation function.
You even get the next two updates to Rybka, as are provided with the standalone version of the engine. So, in my book this is a pretty good deal -> Opening Reference+Strongest Chess Engine Available+Best ICC Interface=Winner. Incidentally, I should mention that Rybka is usable within ICC as an online analysis engine. It can be used for play only with computer accounts.
It looks like this version of the program primarily provides an update to the games database, and that the evaluations and commentary provided in the chess tree are largely similar to the previous version of the program. This is not too much of a surprise, since the 2005 version of the program provided the most comprehensive opening reference available at any price.
I've long recommended this program as a way for people that are unsure about Chess Assistant to try out the interface. All the programs in the Openings series use a light version of Chess Assistant to access the chess data, and this version of the program is no different. So it makes for a good intro to the program - better, IMO than the light version which is available for download.