Interesting. Reia's Tony Arcieri debunks Erlang's "single assignment" propaganda.
I guess someone could argue that once you have multiple assignment you're going to be more tempted to write a longer chain of actions as a sequence of statements rather than composing it out of multiple functions ... and this may be a bad thing.
But I've ranted often enough against languages which think its their job to constrain programmers that it better not be me who makes that argument.
Update : I'd like to see Frederik's question about closures (in the comments of that blog-post) answered though.
Update 2: Ulf Wiger points out that it got answered by Robert Virding later in the comments.