Not really a response to anyone in particular, but just some notes:
If you can get your wizards harla dar necks and 2 high damage long recast spells (ancients or 2 of the new high damage nukes), and mana pres, you'll do really well with them. I twist Ancient Destruction of Ice + Ice Spear of Solest on my main wizard, and Ice spear + Elnerick's Electrical Rending on the others. My macro automatically changes to different spells if a mob is set up as being resistant to specific spells though. I don't run kissassist, but I know with it, you can twist spells really well. Add in a concussion if your main tank doesn't have a BOC.
Oh, mana burn!
Mages are really good again with their burns and fire pets. (Get same stuff as wizards, harla dar necks, and mana pers
OR summon them with the new focus items *wink wink*)
Rangers require very little gear (blessed faydark thunderbolt + blessed mithril arrows) and whatever easy attack gear you can find.
If you're boxing more than one group, you'll want a bard in each group. This is just a must if you're going to be serious about boxing multiple groups. Fast moving, huge mana regen stacking, AE resists, overhaste for melee/rangers. You can do really awesome spell stacking (like 6 or 7 songs on your melee group bards) if you plan them out properly.
Until late POP, their epic is also REQUIRED. Again, if you're being serious about boxing multiple groups, invest in bards + their epics. If you have a 3rd bard or more, you can skip the epic IF NEEDED, as you can dedicate that bard purely to a caster group and just use a drum.
Clerics are mandatory for each group.
A porter (preferably a wizard) in each group. A druid works, and gives you decent heals for rampage tanks and stuff though.
My groups when I'm killing things are:
Warrior
Monk
Bard
BL
Ranger
Cleric
Enchanter
Cleric
Druid
Bard
Mage
Necro
Wizard
Mage
Mage
Wizard
Cleric
Bard
Obviously, I move them around for moving and porting. Raid window FTW on that.
With that group I have 2 casted slows (BL/enchanter) and 2 procced slots (ranger/BL). Also one of my bards twists a slow.
A cleric for AE healing in every group.
My bard in the melee group basically runs a full tank/dps twist and gets resists from AEs from other bards. Cleric gets AE mana from other bards.
I cast savagery on my ranger and monk. Both have primals.
Weapon shield has so many uses as well.
I typically voltron with other people who bring 1-2 groups as well, so we can take out a fair amount of things, including some Luclin mobs, although we don't really go for those.
The more clerics you have, the more you can kill. Once you hit 6, you can take out probably most things in velious, depending on your dps.
Oh, and one thing people who box forget. Dire charm

Turn that buff bitch enchanter into another dps class.
My third bard is set up to twist debuffs, slows, occlusion, and a frost or whatever primary dot resist I'm casting with my raid.
My second bard twists both AE songs as well as some melee songs depending on if the ranger is in that group or not, or more resist dots for dps.
My main bard twists Niv's Harmonic, Warsong of the Vah Shir, McVaxius, and guardian Rhythms (which all the bards twist for max MR).
If you are main tanking on a warrior, get a shield. My warrior mainhands BOC, and offhand swaps between Jaelen's/Horn of Hsagra/Sheild, depending on the fight, or defensive.