"War for Cybertron" and "Exodus" are the "official" histories of the current continuity going forward. Current toys including Power Core Combiners can be accepted as part of this continuity (though their exact place has not yet been developed). This is also the official history of "Transformers: Prime" as well. That idea has not been nixed, it is very much alive (this was discussed at Botcon 2010 with some of the Hasbro folks).
I'm about a quarter of the way in and so far I'm enjoying the book. It takes a much more detailed approach to the history between the Autobots and the Decepticons. It uses a lot of the elements from past continuities including the G1 cartoon, the G1 Marvel Comics, the Unicron Trilogy and even Beast Wars. I can see how the continuities are blending in this new one and I like it. So far so good.