The UMD can be replaced with flash memory solutions.
The PSP dosnt have that many exclusive must have games.
Most of what it does have it could be down as download distribution.
They do it with PS1 games, after all.
I wouldn't call it a minor upgrade. It would change the PSP quite significantly. It would then possibly get a bunch of DS ports, simply because it's easy to do. Never mind original games.
DS ports on the PSP wouldnt attract anyone to buy a PSP, as the DS is better at playing DS games.
The PSP can not overtake the DS merely by adding something the DS already has.
It needs something to put it over the DS, because adding a touchscreen is just like saying;
"Look! We are like them now! We have a touchscreen and we have better graphics!!!"
And that isnt going to attract the majority of gamers.
Not when existing problems (UMD) remain.
I disagree completely. "A bit better at doing the same" is representative of the vast majority of all consoles/handhelds that have ever been released. Are you seriously saying the Megadrive, for example, wasn't fucking awesome? Or that the GBA didn't rock? Didn't those consoles simply do all the exact same things as their predecessors, but a little better?
To start with, worldwide, the megadrive wasnt actualy more successfull then the Snes, and it isnt "better" technicaly either. Its better at many specific things, but internaly they are so different its hard to compare.
But thats getting sidetracked, the important point is no one has ever beaten -their competition- by being "the same but better".
You can beat yourself by doing it, maybe, but you wont get consumers to switch.
The Gamecube was more powerfull then the PS2, but failed to beat it, or even come close.
The Xbox was more powerfull then both, but failed to a similiar degree.
To beat Sony, Nintendo needed to do something different; The Wii.
Doing "more of the same but better" can only work if your already in the lead with no competition doing anything different.