Source - via Shacknews
"For the analog sticks, we did test having the analog sticks on top, since the Xbox has the left side on top [above the D-pad]," Sony's Toshimasa Aoki said. "Especially from the shooter teams--we got feedback that that's what they wanted. They knew that consumers liked the 360 for shooters."
Sony experimented with every possible combination of stick placement, even going so far as prototyping a controller with both analog sticks on top--much like the Wii U Pro Controller (above). However, Sony discovered that it didn't work.
Ultimately, "tradition" was what won out at Sony, with Aoki saying symmetrical sticks are part of the company's DNA. "The prototype team, myself, and also the management team really felt that having this look is the PlayStation look, and we had to keep that."
Shock if old.