Quick heads up: the PDF version has not been updated to reflect many corrections made to the wiki version.

For this reason, I'd rather work with the wiki version than the PDF.

A thread from 2015: https://news.ycombinator.com/item?id=9275336

2013: https://news.ycombinator.com/item?id=6619799

2010: https://news.ycombinator.com/item?id=1378043

there is a v2.0 version of this here, it may still be a WIP: https://www.wespiser.com/writings/wyas/home.html

Author here, yes, It is now complete, or complete to the spec that was originally set.

I'm not very familiar with Haskell - is this still a useful first tutorial or has the language changed too much since 2007?

The areas of Haskell they show haven't really changed in the time since. If you enjoy reading it, I say it's a useful tutorial.