Handhelds and extra analogue sticks: For and Against

Against:

Playing third person 3d games with a free camera(like say, the likes of Mario 64) is disorienting and it harms the portability of a handheld. This type of mechanic is better on a bigger monitor that stands in one place. Unfortunately, this is more than likely what developers are going to do with a right analogue stick on a handheld. They'll probably do it backwards to the Mario 64 standard too.

For:

Games that are naturally twin stick controlled would benefit such as Katamari and Robotron: 2084. Unfortunately this isn't why they're being introduced on handhelds.