I like the return of the voice actors for Superman, Batman, and Wonder Woman. I don't know how I feel about the other JLAers being an unknown Green Lantern, Miss Martian, and Mr. Terrific. And Star Boy... why? I hope it's not because he was involved as an adult Starman with the JSA in a previous universe... I don't think there is a JSA anymore, let alone Starman being stuck in the past with them.

I love Bruce Timm's DC-verse, and I suspect I'll enjoy this. But... I guess I'll echo Mr. Byrne. Hmm.

Star Boy must be coming from the future to warn the League about the Fatal Five, or he's running from the Fatal Five, or something along those lines.

Anyway, this looks like fun. I have no problem with Miss Martian or Mr. Terrific. 

There's many ways to incorporate Ms. Martian.   From converted Mars Imperium/Invader to Cadmus clone of J'onn to a previously unknown Martian survivor (and everything in between).   Heck, if you were going to gender/age-swap a character then J'onn is the most suitable and least offensive candidate.   This is a telepathic alien shape-changer who posed as a white detective in his 30s, an elderly asian man, and even impersonated a lump of living mud -- turning young and female would be like walking to the corner store to get milk for him.   Gender-fluidity (and parthenogensis, by extension) would be second nature to such a species.

As for John Stewart -- he never was Earth's primary Green Lantern was only temporarily assigned to the sector while Kyle was 'away training'.  Maybe we should be more upset about what happened to Kyle rather than John? 

It's too bad we won't get to see this film until the Summer (I'm hearing June).   That's a long time for fanboy outrage to simmer!