I agree, however pushing it to a separate tab is a good idea (to not confuse first-time players). It would have mystified me for a bit, I never even saw percent damage reduction until I got to hell and a Rockfleece dropped. They'd also have to be careful about adding or changing how mechanics work in patches or expansion packs, however Lord of Destruction changed enough about D2 that altering the character sheet would be minimal.
It'd take the mystery out of questions like "does crushing blow from more than once source stack?" and "Do critical strike and deadly strike stack for 4x damage?" (of course the answers are "Yes, up to 95%" and "No", to the best of my knowledge).
I'd also like to see absorbs added to the table of resistances, and physical and magical resist (both in % and simple "reduces damage by x") as well. I hope that they'll include this suggestion, it really hits home for me, though some casual gamers may be overwhelmed by it all. Maybe hide boxes not in use, so there'd be no "total poison damage" box unless you had +poison damage equipped, or a poison spell active.
Perhaps the magical mods will be more straightforward than in D2, like "Increase attack speed by 0.1 seconds / 0.25 frames" kind of thing. This idea gets my total approval
