Which are the best pairs to dual box?

I have a 70 of every class on various servers which I leveled one by one. With WOTLK coming the thought of getting all of them to 80 is excruciating.

I read up on multiboxing and purchased Keyclone. I only have 2 accounts and would most likely be dualboxing toons to 80 in pairs. My toons are on various servers, so I'm thinking of how to consolidate them.

I am hoping that all you experienced multiboxers would give me advice on which are the best pairs to dual-box level together. I tried out my frost mage and spriest today and it seemed to go pretty well and I "2-shot" most mobs.

These are the pairs that I'm planning on leveling. Any input (or suggestions for combo changes) would be great:

Prot Warrior (my main, so i'll definitely be leveling this first) + Prot Pally - I'm thinking AOE leveling

Enhancement Shaman + Subtlety (or maybe combat) Rogue

Shadow Priest + Frost Mage

Moonkin Druid + Hunter

Warlock + DK (when I finally get him up to 70)

I would switch Moonkin with SPriest because with a frost mage and moonkin you would kill anyone before they got to you with starfire and frostbolt.

Death Knight + Paladin

If you can, pair warlock with a class that can heal, because warlock can lifetap. That way, you can go non-stop.

If you use affliction with high spellpower gear, you can enter God-of-death mode where you unload all the DOTs, tab, unload DOTs, tab, and so on. Lifetap to replenish mana, and cast HOTs on warlock.

2 hunters :-)

This thread may help.