> So as a Wine end-user, it looks like this release means no more having to have multiple wineprefixes to support both 32/64 bit applications

WoW64 prefixes have been possible for a long time.

> and also no more need to ensure libraries like libpng zlib etc are installed, either 32 or 64 bits? That seems quite nice

That seems to be the plan, but according the release notes there are still some native 32-bit libraries that will be needed.