Development on the PlayStation Vita hardware may not be final, Sony has said.
The system shown at E3 was "basically the final version" but, according to Sony Computer Entertainment Worldwide Studio boss Shuhei Yoshida, small changes could be made.
In an interview with Weekly Famitsu, translated by Andriasang, Yoshida said Sony is currently gathering opinions from third parties on button positioning.
The Vita features the trademark PlayStation face buttons, two triggers and two thumb sticks.
Elsewhere in the interview, Yoshida revealed that the Vita's rear touch pad almost didn't make the cut. It was originally rejected because of potential costs and doubts over it offering an enjoyable experience. After trying the rear touch pad out, though, Sony immediately decided to use it.
Development of the handheld, which UK shops have listed for £230 (Wi-fi only) and £280 (3G and Wi-fi), began in spring 2009. Sony's developers aimed for both a good price and high quality while constructing the device.
Sony is yet to announce a release date for Vita. At E3 Sony Computer Entertainment Europe boss Andrew House told Eurogamer this was because of production issues caused by the devastating Japanese earthquake.