If you want something done right...

[ButtcrackMcGee]

...you gotta do it yourself. I started dual-boxing a Paladin tank and Druid healer in RDF heroics, alt-tabbing between them to use abilities and its been going great. Took me about 3 dungeon runs to get used to it but afterwards I've had no wipes or deaths, no one can even seems to notice I play both characters (or they do and just don't care). So far I have been able to do all RDF hc, FoS/PoS/HoR/ToC 5 (normal) and FoS/PoS/ToC 5 (heroic). Still didn't unlock HoR HC on druid but I'll probably be able to clear that too.

[Arbiterone]

I've done this once, usually dungeon groups are so slow you can dual box and still play at their level

[Ezrage]

Well, how it goes, we will all need to do multiboxing xD