The people saying that the Healer Tank DPS set up wont' work in D3 are completely wrong. It is true that it isn't necessary, you can get through any difficulty with any group of players, but D3 is set up to allow this sort of group composition and have it work, much better than D2 was.
First off a straight healing utility monk is completely possible and viable. And will still be doing a good amount of damage, while providing utility at the same time to help out the tank. The tank would be doing less damage because they would need more defense, but it won't be as bad with a healer. If your DPS is going to be a WD, then it's perfectly possible that you won't need to have as much control as the WD can handle it with pets, and such. Which allows you to do more damage.
A healing monk can pump out insane amounts of healing, and help control the battle, it is completely possible. http://us.battle.net/d3/en/calculator/monk#eXfWgZ!cdU!YYbcZa
The blinding flash at the end could be changed out for a different control move depending on what you want more. I went a little lax on damage, so you could put in something like Lashing Tail Kick, or perhaps a Spirit Generator if you wanted to generate it in different ways with different effects. I also like the Mystic Ally, but it doesn't fit in as well with a healing set up as other choices.
It's true your damage will be an issue at times, but with a tank and a healer your WD will be able to concentrate more on damage, and less on control. And you will be pumping out enough heals to keep them both alive. So you may do less damage but you'll survive longer.
If your only going through NM though, it may be a waste, you probably won't even get good enough runestones to make this build until Hell, since they lvl of the stone will determine how good the effect is.
But its perfectly possible to be a healing monk, and is an intentional design of the development team, so you can be sure that if a healing monk isn't cutting it, it will be buffed.