Doesn't work in Arc2, but works in Anarki. Also doesn't work with macros, as you say. Macros aren't as big a deal however, because they cannot be shadowed by let or def, only by other macros with the same name.
Personally I think this is a pretty good answer to the hygiene issue. Probably not necessary in every single macro you write, but good if you intend lots of other people's code to use it.
