Ah yeah we don't have hot-updates like Erlang does (we may never, it depends on how Rust would let us do it). That being said we aren't running on a runtime, so Rust code is native-compiled. You could take down and upgrade a node in a cluster as long as the network protocol doesn't change (or is at least backwards compat), but you wouldn't be able to like upgrade a single actor on a node.
I suspect that it would be possible to somehow implement hot-updates with native, if you're willing to use some container as your "runtime". I haven't investigated this seriously, though, so I may be wrong.
