well i duo a shaman as main and an alt mage (4600+ aa's ) and that duo just rock hard.
what i did since i was using the mage pet for the tanking part,was to focus on the aa tanking ability / avoidance at 1st ect.
mage are so usefull for a shaman , can "EASY" coh pull (when u are used to it ),few times i need to cast 2 or 3 coh in row to get what i want,if i can't root it.
my mage is converteum flagged and got the 2 hander from there ( groupable , i even duo'ed him with 2 mercs ) and the augment from fungal forest (forgot names ) but the mana gain from those effect so rock.
2 days ago (august 2nd ) i pwled another toon with my mage in looping planes at north west orc camp (battlemaster area ) since the mobs there are higher level,can be dark blue up to lv 84 ).
my other toon was ""another mage "" lv 83

with few aa's (i use him to farm items like in vex thall ect. with the coh part ).
well most of my dps came from my "best mage" and was non stop killing,chain casting dd's , 2 or 3 mobs at same time (no mercs ,only delayed heal from mage ) to get better xp,and i chain killed for 1 hours non stop (since the weak mage had lotd running and another one gtg ) and i didn't had to med once (was casting the 3100 mana rumbling servant pet when i had mana gift tho (one mana to cast ) .
just to say : KEEP leveling that mage and u won't regret it

my mage got minion 8 focus btw..