The article had no mention of Alduin's dual identity, even though there was a description of him. I'd venture to say that if it isn't in the description, would it be possible that they ignore it in the game? What other established lore would they skew? All those dragons that have been banished for a thousand years? how is this going to impact lore, being such a huge contradiction? I know it's still a little to early to be so accusatory, and I hope the lore discrepancies are entirely GI's fault, but I can't be sure.

http://www.gamesas.com/index.php?/topic/1152130-the-story-behind-skyrim-v20/

Alduin and Akatosh aren't two different identities. It is the same Aedra/entity/god/whatever-you-wanna-call-it, viewed and named differently by two separate people. (Nord and Imperial)

I'm pretty sure that as far as Alduin goes GI only failed to mention them because:

1. They probably didn't even know about it.
OR
2. They didn't want spoil the fact that the destroyer of the world is also among the most revered (supposedly) gods of the Elder Scrolls universe. That information in a clueless person's head can spoil a lot. For us that do know about the connection anyway, there isn't much that wouldn't have been spoiled either way.

And this is assuming that Beth hasn't butchered the lore again, making Alduin take leaf out of Jygallag's book and going even farther than he did.

However, as far as the Dragon's being banned for a thousand years goes, its possible that it was just one of those things that the line of Emperor's (Dragonborns) keeps secret. A quintessential Area 51 passed on to each Emperor so they know whats going on in regards to the Dragons. After all, we know from previous lore that the Empire does have the ability to unbanish Dragons, hence the Dragon from Redguard, who, iirc, also fought for the Empire. So it only gives itself to the possibility that the line of Dragonborn kept the fact that the dragons were banished a secret for however long and its only now that the Empire is in quintessential shambles (the secret having never been passed on to an heir to the Throne, only surviving in the few Dragonborns left at this point that had no claim to the throne, pretty much) and the Dragons beginning to return on their own that the secret becomes prevalent in history.

All in all, I'm pretty sure as far as Dragons and Alduin goes, Beth is maintaining the lore, and bringing in new lore to supplement what we couldn't have possibly known from the previous games. The dragons were always banished, we just had no reason to be made aware of that fact as it was, most probably, a secret held by the Empire that manages to keep for a very, very long time. (as to how the Dragons came to be banished, and why they were, we can't possibly know yet, other than it probably had something to do with Alduin/Akatosh. My guess is dragons get frenzied by Alduin when he comes and the Dragonborns decided to just banish the dragons somewhere rather than risk them destroying the world, even though the main problem was Alduin anyway. I'm probably way off)

Sure, the god is the plane, and they share a plane. That doesn't mean they can't be separate personalities (consider the plot of SI).