4th edition does have more backgrounds then 3rd.. it was a conscious choice.
One of the preview books mentioned that it was a problem with a lot of the art, "dungeon" is right there in the title, but you dont get a feel for that looking in the older books. That's why a lot of the 4th edition pictures are big squares with backgrounds, or the ones on white usually have pieces of floor.
But I've noticed it's been getting worse since the the launch of 4e..
Indeed, a great deal of the concept art for 4th Edition consisted of nothing
but background landscapes; it's hard to forget that the 'spirit' of the 4th Edition Points of Light setting was captured perfectly by this image:
World and Monsters itself presented a principal design concept concerning 4th Edition, to be kept foremost in the minds of authors and designers for the edition. Stacy Longstreet, writing under the heading "Art Direction for the New World" said:
"Another observation… was the overall lack of world imagery—what the world actually looked like. So many pieces of art showed items or adventurers, but with little to no visible surroundings. One of our goals this time around is to add more flavor and to include art that shows off the world, with its vast range of environments and locations. [1]"
Clearly, then, background imagery was an explicit design goal of 4th Edition.
The open question is one of whether or not this goal is being met with current releases.
My own—subjective and unscientific—observation is that books containing relatively more 'fluff' also contain more art with backgrounds, and books containing relatively more 'crunch' contain less art with backgrounds. For example, there is much background and location art in
Manual of the Planes, noticeably less in, say,
Martial Power, and virtually none in
Adventurer's Vault.
I would assert, based on these observations, that Longstreet's goal is
not being met: the art of 4th edition is showcasing the "vast range of environments and locations" only when such things are the focus of the book, e.g.
Manual of the Planes.
I am somewhat disappointed by this, and hope that it changes as more material is released, but it has not seemed to be the case so far.
—Siran Dunmorgan
[1]
Worlds and Monsters, p. 15