Why A Game of Thrones Will Fail

I know, I know.  A lavish production based on a set of best selling books with big name stars, airing on HBO.  And one episode in and here I am predicting its untimely demise.  Why?

The problem is primarily one of scope.  The books, and hence series, are based on a large world with a vast cast.  Other series and movies have also had to deal with geographically diverse locations - I'm thinking of the Lord of the Rings, here - but they've only had to do so piecemeal.  Whilst the Lord of the Rings had to deal with the Shire (and its hobbits), Moria (and its dwarves), Lothlorien (and its elves) and Minis Tirith (with its men) it was able to do so in small, bite-sized chunks.  We get some time in the Shire, and only in the Shire.  Then, things move on, we forget about the Shire, and the film can go on to explore Moria.  We see, we enjoy, then we move on once more.
In other words, movies like Lord of the Rings can handle the large map by progressing through it in a linear fashion.  The Game of Thrones cannot do so, as the cast either communicates with one another across the distance, or actively jump locales in order to discuss events more intimately.
Which leads to the second and greater problem of having a vast cast all interacting pretty much simultaneously.  With so many characters being thrown at the screen, in varied locations, with multiple plots (current and historical) it is a non-trivial task for those not familiar with the source material to keep track of what's going on.
Which will lead to a rapid rate of attrition.
And, worse, those who haven't seen the initial episodes will be unable to jump in mid-season.  This problem will be familiar to the creators of many recent shows that evolved complex storylines and character relationships, though I doubt many had to endure such a viewer-antagonistic opening.

Finally, for those who are unaware of the *layout* of the series (no spoilers, not that I can, as I haven't read it), the later books famously drop an entire half cast off to go and focus on the other half before picking up again.  As the series is pretty much following the books (in a season-per-book manner) then it will be interesting to see how later seasons (should they get that far) translate such material.  You can't really tell half your cast to take 2012 off and come back in 2013.  And I don't think they can use the standard mechanism of just deviating far enough from the material that it's not a concern (a la True Blood / Sookie Stackhouse) as the Game of Thrones books are much more intricately tied together than other, more stand-alone books.

And of course it's made just that bit more difficult by the fact that the book series is still being written.

Upon the strength of the above arguments, I'm going to say that it will stave off a push for cancellation during the first season (based on money sunk, and against high costs per episode), but it will succumb to cancellation before the end of the second season.
Box sets and equivalent will do well, however.
Goodbye, Winterfell, it was good knowing you.
Call me in 15 months and tell me how close I was.