Looking at the Dominion articles, nothing but melee characters are shown
 

Guessing squishy ranged characters will be applicable, will they?

I don't see why they wouldn't be.

annie and ashe are in the video. however i think annie will b worthless in this mode along with the other burst mages.

Well, looking at the map from the video and screen shots (I did make the mistake of saying all melee, Ashe, Annie and Lux are shown), it looks incredibly small with gap closers being very, very effective.

And you have to put yourself at risk to achieve an objective anyways. It also looks like there is almost no way to farm, so the characters who don't need a lot of it at level one will dominate (XZ, Garen, Renekton, Jarvan, etc.)

Kind of just answered yourself there.

Yes, they would have a hard time holding a place down, as they're squishy. But when the enemies are holding someplace down, they can stay back and take them out, letting their team go in and take it.

I can see burst mages being played as assassins, since in order to be able to hold so many points scattered around the map, you team is almost required to split up.

I highly doubt they will just let Ashe sit there and pluck at them. Especially one with almost no items

Yeah, this is gonna make a lot of people rethink how they play various champions.

Yes, but if she had teammates with her, what are they going to do? Leave the post and engage on an unbalanced fight and die? No. I don't exactly know how the mechanics of this game are going to work, but ranged players seem viable, as long as there is only one of them.

It will be mostly bruisers and tanks with a mixed bag of others just like treeline I imagine (different mixed bag but a mixed bag nonetheless). I imagine TF, Nocturne, Nidalee and other champions with high mobility will be invaluable for their map presence. Ashe and other similar champs who need farm are gonna be useless. I imagine based on the spacious lanes and clearings shown in the video the Anivia's wall will be significantly less usefull.