Do non-team people post here? Apologies if not, but here goes if so.
For what I’m using rust for, game dev, I’d like to see libs that are no_std whenever possible, and for things that might otherwise just be std to make it all the way to core whenever possible. If this means that the no_std build has only partial features that’s fine too (example: rand can still run an rng using core only even if you now have to seed the rng yourself somehow instead of using the csprng from the OS).
This also means hopefully having some types that accept some memory that I give them, use it while they exist, and then go away without ever allocating/reallocating/de-allocating. I just want a nice interface over what I’ve allocated. For being a “systems language”, rust seems to be somewhat lacking in low level support of that kind (no one on IRC knew of any existing type that did something like that). Obviously there are a lot of catches and such, but those can be ironed out with careful thought I hope.
I’d also like to see crates and libs that have very clear interfaces towards solving whatever problem they solve. Preferably with little 10 or 20 line demo programs that show how you use the crate from start to finish. Rust can get a little Trait happy and doc light, and that can make coming into a library get confusing fast. Hopefully traits could say things like “you should implement this trait on your type if it does X and then it will work with this library” or “values with this trait usually come from the Y or Z methods”. Things in core and std do this quite well, but things outside that usually don’t do this so well.