We don't want a flawless Diana as much as we don't want a generic action girl Diana.
*I* kind of do want a flawless Diana.
I don't understand the need for big-screen heroes to ALWAYS be flawed, relatable, "human", etc. Sometimes, I just want to see someone who is larger than life, who is better than everyone around them, someone who is truly heroic and inspirational. Sure, it's escapism at its best, but it's a worthwhile form of escapism to have a flawless "idol".
Also, if Wonder Woman is immortal, or at the very least has been alive for thousands of years and has been "active" in man's world over hundreds of years (either continuously or periodically), then I'm not sure that some of her "traditional" flaws would be appropriate.
This version of Wonder Woman doesn't appear to be at all naïve about man's world (based on the few glimpses on the trailers and set reports) since she has openly adopted current fashions, technology, transport, etc. I guess she could still be "naïve" about certain customs/cultures or even inter-personal relationships, but that would seem unlikely and somewhat ignorant of her.
And if Wonder Woman has hundreds of years of battle/war experience as the leader of a powerful army, I'm not sure she would lack confidence. Not only is Diana the champion of the Amazons, but she's also their princess.
As for being trusting, I thought that this quality actually worked in Wonder Woman's favour in the New 52 reboot. Yes, Wonder Woman trusted everyone, sometimes to her detriment, but that same trust led to many former enemies (e.g. Hera) eventually becoming her allies because she placed and maintained faith in them to do the right thing (and because she "loved" everyone). Also, if Wonder Woman's trust was easily misplaced, then I would have expected her to learn her lesson over her many years of experience in man's world (and even amongst the Amazons).
Again, based on the (very) little information available, the more likely flaws for this version of Wonder Woman would be arrogance and maybe a dismissive attitude towards others/lessers. Possibly also selfishness, although if Wonder Woman has been "secretly" helping man's world periodically over hundreds of years, that doesn't seem to be very selfish.
I would be happy to see Wonder Woman's character called into question by Batman, Superman and others as they question the motivation behind this "goddess" assisting lowly mortals. And I'd also be happy to see conflict between Wonder Woman and Queen Hippolyta about Diana's role as champion and princess of the Amazons, especially if that conflicts with her super-heroism. But, I'm not sure that means that Wonder Woman has to be "flawed" in order to encounter personal conflict.