I don’t see the reason so many people are clamoring to make ETFs less transparent (usually 99% of the people don’t need to mask their trades). In general people don’t like transparency for two reasons – they are doing something they shouldn’t be, or, they are revealing they are not doing anything significant and charging a lot for it.
However, this article touches on a topic I would love for the regulators to approve, and that is NAV based trading for ETFs. Would be the nail in the coffin for mutual funds.