Even though Revit PDF Writer is no longer supported and not present on 8.0 download page you can still get to it. While looking on download page
http://revit.autodesk.com/download.asp select a language different from English in the drop down at the top. You will be redirected to a 7.0 page in other language and will find Autodesk Revit PDF Writer 4.2 on this page. I think downloaded PDF Writer will come up in English even if taken from foreign page.