I have a feeling they have two different goals for the Xperia phone and the NGP. NGP is suppose to continue the line of videogame handhelds and given its specs, probably offer console developers a similar platform as the 360/PS3 to port their games from.

While the Xperia phone is meant for PS1 games, and other Android games that other similarly specced Android phones could probably play. So basically the controls would set it apart from other Android phones.