tEh GRAFIX are PS2-ish on the iPad and will be the same on the iPad 2 -- just a way better fill rate I'd assume based on the marketing.
Shader requirements? Kind of like how PC games require a certain Shader level, like 3 as an example?
iOS support up to OGL ES 2.0, which supports shaders, but it's not really a requirement, since one can still use OGL ES 1.1. I just started working with this in the past year and seriously in the past few months, so that's my brain-pacity on the subject.
The game should be reconfigured to run on an iPad.
Games like World of Goo as an example are fun on an iPad, or any tablet for that matter, and work well, but it IS still easier to play with a mouse, or with the use of a capacitive stylus.
I think Diablo with a stylus could work, but after just finishing DeathSpank, which is a wacky Diablo type game, I'm not sure I'd want to play this sort of game on a touch screen.
Based on my experience I think my hand and my arm, would get really tired. The iPas just isn't good for fast repetitive actions. With a mouse your hand is always resting and can perform big movements with minor twitches, this is not the case on a touch-screen, which requires you physically move to the point you want to touch.
Even classic Graphic Adventures don't seem to work that well on a touch screen, but this is more so because it lacks a hover state and some companies don't bother to put in a button to toggle it on and off.
Anyways, there's way more to this, but outside of casual, turn-base strategy, etc., most games really don't work that well on a touch screen. For the few that do, like World of Goo, it adds a dimension of fun.
There's more to this of course.
