I'm REAL curious to see the armor table now...
If you remove the exotic armors (yay, btw), then there are only two light armors (both 11+dex),, three mediums (12/13/14 +1/2 dex) and five heavy (14-18). That makes heavy very top-heavy, light almost pointless, and medium kinda a wash. While I realize they want bounded accuracy/low numbers, they need to revise that table to even it out.
I wouldn't be surprised if hide or studded leather doesn't end up light, chain or ring ends up medium, and the chart steams from 11 to 18 (plus various amounts of dex, determined by type).
They say they have "done a lot of work to tweak the flavor of the armors". I hope this means there is something to differentiate them other than increasing bonuses.
My guess it that we'll get a smaller armor table than e.g. in 3e, maybe 6-8 armors and that's it.
Which is actually quite the opposite of what I would like... I would like a good
15-20 armors to choose from already in the PHB. It shouldn't really be hard to design that at all, but I suppose the topic is not especially popular among players and the designers believe it's not worth the design effort.
15-20 armors allows both a wide range of
narrative choices (e.g. player #1 chooses armor based on the image of a movie character he likes) and
tactical choices (e.g. player #2 chooses armor based on minor interesting properties), pretty much like weapons.
A long list is not a problem for beginners: they have
starting packages which choose default weapons and armors for them, so they don't have to go through the list if they don't want to.
With no fantasy armor in the PHB, the armor list will definitely contain
anachronistic armors, i.e. armors which did not exist at the same time in any historical period. But I think this anachronism is actually very "D&D", which itself is always a hodgepodge of stuff from different cultures, historical period, and mythologies. I mean, seriously it bothers you to have a "bronze plate" armor warrior in your party but it doesn't bother you to have a Shaolin-based Monk?
Definitely many of those armors would have the same AC.
Minor properties will make them different. It's really easy to design them: take a reference armor with AC=x, then derive new armors with AC=x-1 (or even AC=x-2) but an additional property such as extra protection against critical hits, better for stealth, lesser speed penalty etc. Just as easily, you can derive armors with AC=x+1 if you add a penalty.
Or just take a look at armors already designed in 3e (between the PHB, the early splatbooks, and the Equipment Guide, there were surely more than 20 armors) and adapt them to 5e.
There can easily be one armor per category without any additional property, for those who want a
low-complexity armor that only grants AC.
Don't use
market price as a balancing factor! Given the 5e assumptions on treasure and wealth, this would be wrong! Use it only as a
narrative factor, such as if armor X is typically very expensive then it means only the rich or the veteran adventurers are expected to afford it. In any case, after a few levels the costs become irrelevant, and such balancing factor disappears, thus better to avoid altogether.