Charles Stross weighs in the whole online controversy over George R.R. Martin taking his time to finish the "Game Of Thrones" series, and he has some useful perspective. Stross, whose "Merchant Princes" series is long and sprawling in its own right, explains that there are actually two kinds of multi-book series, and why "Game Of Thrones" is the harder kind. (And he explains why you should beware the problem of the spear-carrier who sneakily becomes a protagonist!) [Charlie's Diary]