A google search for "dhammakaya site:dhammawheel.com" should give you quite a bit of information.
They seem to be putting on a big show impressing a lot of simple-minded people, attracting rich people who want to buy merits. That's my impression.
And to "inner circle" members they seem to teach some rather strange esoteric doctrine not dissimilar to scientology. This "insider report", which was posted in a recent topic here, seems quite revealing in that respect: http://blogs.dickinson.edu/buddhistethics/2012/07/17/esoteric-teaching-of-wat-phra-dhammakaya
And these big and pompous mass gatherings, and events like this, http://www.dhammawheel.com/viewtopic.php?f=8&t=11215
, what does that have to do with Dhamma? It's a shame. It's a sham.
I'm almost waiting for the day when my old father will want to go to one of their temples with me to do me a favour because "I'm interested in buddhism", and this is the biggest, blah blah blah... Heaven forbid...
And if that's what future generations in our commercialised world will associate with Dhamma if they ever hear of it and look for it, even in Buddhist countries like Thailand, then...
Okay, maybe we should not all be so pessimistic as I am, but wary in the face of such blinking shining advertisement. The Dhamma is humble. It does not put on a show and is not to be found in the spotlights.