Lies, damned lies, and, in this case, not even statistics.<p>To me, the recent drop doesn't look much different from the one around July 2012. It may show some plateau after the initial drop where the July 2012 already started edging upwards, but I doubt any statistical test would support the claim that there is a definite drop recently. But convince me.
Subtlepatterns.com is hardly a bastion of skeumorphism. Sure, there are some "realistic" textures there, but they account for probably less than half the textures, and, more importantly, they're not used for UX. The problems with skeumorphism have more to do with confining UX to realistic actions than making things look realistic, and subtlepatterns only barely qualifies for even the second case.