Harry Potter and Eberron
Here's an interesting thought: Harry Potter is a higher-magic world than Eberron.
This is not strictly true. I've never really seen anything in Harry Potter that really compares to the destructive power of a fireball. (Most of the Killing Curses are against one foe only).
Why I initially made that comparison is because there's a lot of low-level magic in Eberron, accessible to everyone. This is also true in Harry Potter (amongst the Wizard community only, of course). I know that Harry Potter is in a "modern" society, and there are plenty of other differences between the two, but there's a familiarity to it that is quite a contrast to the low-magic tales of someone like Howard.
We can also see resonances in Piers Anthony's Xanth books (everyone has a magical talent, normally minor), and likewise in the Black Jewels trilogy by Anne Bishop (the witches can do a lot of household chores with magic, in additional to the more serious uses).
That this is occurring in fantasy literature may be a reflection on modern society, where the tools we have available to us are much more advanced and pervasive than even 50 years before. (Consider the computer... or rather, don't. We don't have the time.

)
One common tradition in fantasy books is to severely limit the use of magic. It's there, but only a couple of things can be done with it. That style of magic has never really been the style of D&D. One reason for that may be that D&D requires a variety of challenges to remain interesting, and magic is the tool that is easiest to use to give variety.
Another thing that comes to mind when comparing books and D&D is that most D&D games don't have much of a clue of how to do intrigue. Well, sure; it's meant to be there, but the execution of it is often something that the DM knows about afterwards, which isn't very rewarding for the players.
(The Eberron adventures I've seen so far suffer from this greatly, IMO).
Writers like Leiber, Edgar Rice Burroughs and Howard are very important for the form of the traditional D&D adventure: crawling through pits facing challenges. I'm not sure how many of the current fantasy novels really promote that style of adventure.
This may not be a problem, but it does bring up a question: The world of D&D has changed over the years. Has the stories we tell in it changed as well?
Cheers!