The style does not appeal to me, but I am enthusiastically in favor of moving away from the "clasped and jeweled tome" look of 3E. I feel that kind of art does absolutely nothing to convey the spirit of the game.
I prefer scenes to portraits or illustrations, but as long as the books show appropriate art, I'm all for it. (Appropriate in my opinion - big monster, preferably a dragon, on the monster book; wizard or controlling overseer exhibiting vast power on the DMG; mix of varied characters exploring the unknown and invoking a sense of wonder on the PHB.)
I think the text should be less "logo-ish" with the artwork more predominant, as well. The art should leap off the book to interest new potential players. The effect should be more "Wow!" and less "This looks like a series, is this the first one? It's not numbered either."