alt Hacker NewsThere's some movement on specialization as well: https://goals.rust-lang.org/2026/specialization.html
It's not directly blocked on the solver, but getting the type system into a better shape definitely helps reasoning about the soundness issues involved.
More precisely: it wasn't known to be blocked on the new solver (unlike some other features), because nobody dared to touch it until recently... (more seriously, there wasn't enough investment).