Kojima Productions is currently making changes to Metal Gear Solid Peace Walker's controls. The changes are being made at a "rapid pace," according to a recent post on Kojima Productions Official Website, known as Kojiblog in Japan.
Kojima Productions has used, "impressions from the press, opinions from management, direct opinions from users, surveys from users in the demo area, opinions from the web, opinions from message boards."
The TGS demo offered players selectable "Shooting Type" and "Action Type" controls. These existing control types will see some fixes. Additionally, the team is considering offering a third control scheme:
"PW will be 'The Action Game on the PSP,' so we'd like to be particular about the control method and the feel of control until the end," - Kojima