I've gotten 3x drakes multiboxing (2x via pugs), imo the eziest way is just pugging it with each character, if you go in with a tank, healer, + a few AOE type classes its super easy. That said, i'd wait till next patch, dropping a few magma totems will make zombie clearing a bit faster plus extra shaman DPS should help out a lot. I used feasts when I was farming, and of course if its not obvious you should do the drake boss before you do Malganis. I take my mage so I spam drink whenever I can since I have 4 stacks of water on everyone

Back to the original topic, two things I'm considering doing are getting a Thunderfury crafted, and maaaaaybe making 5x AQ scepters. The thunderfury is pretty straightforward, run Molten Core till honored or revered (do Baron quests too), and farm the 2 guys that drop the bindings each week till you get em both, then kill Rag and kill the windseeker. At 70 I wiped on the 2nd trash pack in MC due to the silence, gonna revisit at 80 this week and see how it goes. My DK is only level 56 but I'd like to level him to 80 and get a Thunderfury for him (or my pally, or both! haha)

The AQ scepter is much more interesting, you have to farm AQ40 until friendly, then kill the 3d boss in BWL 5 times and Nefarian at least once. The chain is insanely long, but I think a multiboxer could handle everything except the BWL part no problem. Not sure how BWL would go solo, I might give it a whack this weekend but not optimistic about even the first boss. Once you finish after a few weeks/months the scepter is pretty useless, until a new x-ferable server opens up or your server gets free xfers to a new server. Even then I don't know the rules anymore about Blizzard AQ40 opening, do new servers have the gong ringable immediately, after a few months, or not even an option? Would be good to find that out first, lol.

You could also try farming Kael'Thas in Tempest Keep, but I don't think 5 man could do it at 80. I went in for fun late last night with a raid and even with 25 80s most of the people died before Kael was down (no strat we just ran in and started fighting lol). Mount didn't drop of course, but it would be insanely awesome to have that flying phoenix mount.