The only chance Sony should make is to add two extra triggers for Vita 3000 and take out the rear touch pad. Period.
L2 and R2 buttons would be great!
But don't remove the touchpad, it actually has very useful functionality in some games, such as adjusting sniper zoom in Killzone. Also, no touchpad would make Remote Play impossible, unless they also make the sticks clickable (L3 and R3).
"Never argue with stupid people. They will drag you down to their level and then beat you with experience."