Scribe Ineti
Explorer
While gaming stores seem to have new releases displayed prominently, any major book store I've been in has their D&D books kicked away in a corner, with only the spines showing.
All three of my local Borders stores have endcaps with assorted D&D books faced out on display. The RPG books have been lumped in with the manga and young adult books, but they do display some covers.
Both my local BAMs have the RPG books on shelves, mostly spined out but some are faced out, depending on how many they have in stock.
One of my local Barnes and Noble stores has a 7' spinner rack on the floor near the sci-fi/fantasy section that contains D&D books, 3 racks with four slots per rack, so it can display up to 12 different books faced out.
I remember seeing at some point, a cardboard display box like the in the picture above. I think it had the PH1, PH2, and DMG in it. Not sure. But yeah, more visible displays would be nice, though I know publishers pay the bookstores for that display space. I guess if WOTC's marketing department paid for the space, they'd get good displays in bookstores.