What you guys said was that your main hand attack speed gets increased by 15% when dual-wielding. Fine, that may be true. But, it would make more sense if dual-wielding just increased your over-all attack speed by 15%.
"The Exploding Palm DoT does a base 65% weapon dmg per second, if a monk is using a 1.2 APS weapon the DoT will now deal 78% (65 x 1.2=78) wpn dmg per second. A dual wielding monk with a 1.2 APS main hand weapon will deal 89.7% (65 x (1.2 x 1.15)=89.7) wpn dmg per second."
What you suggest is that a 14.5 dps main hand weapon together with a 2.5 dps weapon in off-hand would produce the same dps as a 14.5 dps off-hand. That could be true, if the DoT dmg is only based on the main hand dmg, but to me, it sounds like a really crappy design.
What would make more sense is that the dot dps is based on an average dps from both weapons multiplied with 1.15 for dual-wield attack speed bonus.
I'm not trying to disprove you, but are you really sure that you are correct?