The new icons look really good, but unfortunately they are not really fulfilling their full purpose. The purpose of an icon is primarily to make it easier to distinguish between different communities in this case. The most noticeable features of these icons are the outer shape and the colour scheme, this makes it easy to distinguish between Beehaw communities and non Beehaw communities (so far so good). But it almost makes it harder to separate between the different Beehaw communities, since that information only resides within the inner symbol of the icon and that is far less prominent than the color and the outer shape. Unfortunately, we tend to think things with symmetry looks better, which makes a good looking icon theme and a usable icon theme a bit orthogonal.
So, while I really like the look of the icons (and how they tie in to the Bee theme of the site), I’m not a fan of the usability aspect of them.
My impression is that it is just someone who created a community for each language they could think of. But if programming.dev is a popular instance that is well managed, then sure. But for now, it seems that lemmyrs.org have more users and momentum.
EDIT: On a closer look, it turns out my first impression was quite wrong. programming.dev seem like a quite well managed place, so I do not have anything against using that as a base for rust if that is what the rust community chooses.
As I mentioned in later comments, my first impression was nothing more than a first impression. When I learned that it was not just some random person that threw up an instance but some respected mods I circled back and had a closer look. And at a closer look, I admit that my first impression was wrong, it seems like a quite well managed instance with great potential. I actually created an account that to evaluate that, to see where I finally will end up when the dust have settled. So thanks for your effort, and sorry for my poor first impressions. But it really doesn’t matter what I think, what matters is where the prominent rust front figures choose to hang out, I hope that will include one of the lemmy forums.