XanaNews works even in Vista 64 bit, it appears from comments:
http://www.wilsonc.demon.co.uk/xananews.htm
This incomplete listing of newsreaders doesn't say which work with Vista:
http://www.newsreaders.com/win/clients.html
It is possible to run XP on a virtual machine in Vista. I think Richard Urban
said he was using OE instead of WinMail while running Vista via a VM. To
run Outlook Express you need XP. You could dual boot - that's what I do,
but I recently installed Microsoft's VM because I'm looking to get both at
once rather than either one or the other. You could investigate newsreaders.