More diversity of accents would be nice in-general. I'm British (more precisely, a Scot) and I can't stand the thing where all humans sound like Americans. It just seems artificial and presumptuous.
The idea of somebody who actually believes in God, particularly if he/she were a scientist, might be genuinely interesting if written in an intelligent, sensitive way and there was none of this "silly supersitions" thing that Roddenberry was so keen on, after-all, the Bajoran religion was well handled I thought and they were really rather devout.
Racial diversity in the Captain's chair is probably logical (after all, putting a white American in the Captain's chair in Enterprise seemed like a step backwards) and most likely a man, it would be tough to have two things at once, both female and ethnic somehow. Either that or settle for a woman but who doesn't sound American, but that is still loaded with the problem that women often sound school-marmish when disciplining others, a problem Janeway had and women don't necessarily make the best action-heroes which if you want to "get back to exploration" is exactly what you want to do.
They seem to be into the idea of picking an enemy species and embedding them in the regular cast to explore them more and somehow bring them around. They did it with Klingons, Changelings, Ferengi, the Borg, is it too much to hope that they won't do that with Romulans, Cardassians, or lord help us, the Breen? If you are going down that route, why not pick a second-tier species, Bolians, Benzars, Tellarites, whomever, that we've seen but don't know that much about and run with that.
One thing I would like though is a relatively small group (smaller groups are easier to write for and to ensure everybody gets a reasonable amount to do) with clear, definable differences in personality, interests and talents from each other and what's gone before. I don't want repeats of the past but I also think that despite the fact that the Outsider commenting on humanity works very well as a whole, its been done to death with Spock, Data, Odo and Quark and Garak/Dukat/Female Changeling/Weyoun when they were there, the Doctor and Seven and T'Pol and Phlox and Soval/Shran when they were about all serving that role. We know we are illogical bunch, probably better to move on now 'cos its wearing thin as an idea.