I would like to see the option to have the character screen's displayed stats change when you change an outfit.

Most classes that have multiple sets of gear also represent different stats with each set. One set for casting, one set for tanking, one set for physical dps, etc.

For example, on my druid alt:
I normally run around in my cat DPS set, and have my character screen display "Base Stats" and "Melee" stats. However, when I switch to bear gear, I like to see my "Defenses" stats on the character pane. Similarly with healing gear: I need to change the displayed stats to healing.

I think it would be great if the user could choose which two PLAYERSTATs to display for any given set.

The variables controlling these are located here:
...\WTF\Account\<AccountName\<Server>\<Character>\SavedVariables.lua

with data:
PLAYERSTAT_LEFTDROPDOWN_SELECTION = "PLAYERSTAT_BASE_STATS"
PLAYERSTAT_LEFTDROPDOWN_SELECTION = "PLAYERSTAT_MELEE_COMBAT"
PLAYERSTAT_RIGHTDROPDOWN_SELECTION = "PLAYERSTAT_RANGED_COMBAT"
PLAYERSTAT_RIGHTDROPDOWN_SELECTION = "PLAYERSTAT_SPELL_COMBAT"
PLAYERSTAT_RIGHTDROPDOWN_SELECTION = "PLAYERSTAT_DEFENSES"

I did not find any specific function on http://www.wowwiki.com/API to change those, but using a macro works.

/script PLAYERSTAT_LEFTDROPDOWN_SELECTION = "PLAYERSTAT_BASE_STATS"
/script PLAYERSTAT_RIGHTDROPDOWN_SELECTION = "PLAYERSTAT_SPELL_COMBAT"

I just dont have room for a macro for every set. :)