From Dechen Norbu (with metta to him and respect.) in a thread that was locked, in a response to nowheat :
"What you present here is not Buddhism. It’s a sterile and degenerate version of it, built to fit a materialist paradigm and conform to the state of affairs of scientific knowledge of this day. It’s no better than any other shoddy self-help system."
Now I've not read through the whole thread and I'd guess nowheat could've maybe explained things better, or maybe even had a faulty conception of what Navayana could actually be, but I don't see it as degenerate, materialist, western-style scientific (As a westerner I loathe the western reliance on the current type of science and how it refuses to be open minded and research several areas properly and with the right funding.) or a shoddy self-help system.
The Buddha said in the Kalama Sutra :
"So, as I said, Kalamas: 'Don't go by reports, by legends, by traditions, by scripture, by logical conjecture, by inference, by analogies, by agreement through pondering views, by probability, or by the thought, "This contemplative is our teacher." When you know for yourselves that, "These qualities are unskillful; these qualities are blameworthy; these qualities are criticized by the wise; these qualities, when adopted & carried out, lead to harm & to suffering" — then you should abandon them.' Thus was it said. And in reference to this was it said.
From George Beoree :
"It is, of course, a little presumptuous to say which of the many sutras are the ones we should pay attention to, and which should be considered some kind of later addition or modification. We will never know exactly what the Buddha said and did not say."
This is true. You can say teachings have been passed down throughout thousands of years, but we don't know what exactly is taken directly from the Buddha, what was taken as notes from his original teachings and then modified by followers throughout the centuries, what was added, what was taken away, what was mistranslated and so on. Unless your insight has allowed you to recall a past life where you were extremely fortunate enough to have been sat with him and listening to exactly what he said, you do not know.
You can talk about hells, heavens, karma, rebirth and so on, but if you don't have direct experience you cannot know any of this for a fact. You're using faith, not direct knowledge. You can trust all the elders and teachers you want, but the Buddha himself said not to go by this, he said to only accept it fully when you know that wrong views, methods, etc, are unskillful, and so on.
So Navayana can and probably will exist as time passes, and I just hope it treats the teachings that are around with respect.
My own take on karma, hell, heaven, gods, goddesses, rebirth, angels, demons, buddha lands and so on is this : I don't know they exist so I will not believe in them unless I have direct experience. But, and this is the final and most important thing that I think is of total importance if Navayana is going to work at all : to not reject karma, hell, heaven, gods, goddesses, rebirth, angels, demons, buddha lands and so on. It's to stay open. To not close their minds to any of these things if some take the decision to break off and go their own way. Neither reject nor accept, but to practice until direct knowing is attained.
Two final things :
1) The Buddha, once enlightened, was said to have exhausted all his karma so that he'd never be reborn again. This to me makes no sense. If the Buddha upon being enlightened has the complete freedom of the Dharmakaya, he is then free to do what he wants. So if he decides to come back, he can, because he has absolute freedom to do so if he chooses for the sake of helping others.
2) When other schools of Buddhism started out, do you think the other Buddhists were like "Yeah ok, go ahead, no probs!" If the Buddhists that began the Mahayana were so worried about what other Buddhists thought wouldn't it be the case that we'd not have the Mayahana, we'd have Theravada and that'd be it? So your teachings, your schools, this forum and so on, wouldn't be here.
If people go ahead with this in the future, the best thing that can be done is to support them, help them out of compassion, help guide them, and remind them that even though they don't agree with certain things, it'd be wise not to discount any of them at the same time because ultimately in their current state they can't say one way or the other. Let them stay open, use what works for them, the Eightfold Path, Zen methods, Vajrayana methods, Theravada methods and so on. But they shouldn't be treated as outcasts if they have respect for the Buddha and parts of the teachings that can lead them to awakening.
Navayana can work if it's done properly. There's been many different schools in the past. Does living in the current time carry a rule that nobody is allowed to create a new school? No it doesn't. I'm just hoping that if it's done they're not treated overall in the way that I think many will treat them.
What concerns me the most about all this is that even if the next Buddha where to appear in the word today and say he's creating a new vehicle to work best with the current times, he'd probably be rejected by huge amounts of Buddhists as a charlatan because people are so entrenched in their own schools.
Nothing of what I've said was meant to offend or attack anyone, I'm just saying what the situation looks like to me regarding this issue. For anyone offended I'm genuinely sorry and metta to you. Besides, the more awake you are the less some words on a forum are going to bother you anyway.