I've got "Open safe files" checked, but Realplayer files still only download for me. This is using Safari Version 2.0.3 (417.8) on OS X 10.4.5.
The really funny thing is that it definitely was working properly, but then abruptly stopped after Realplayer told me I was out of date and needed to download a new version. I hadn't yet installed it, but I had downloaded the dmg and Safari had automatically unpacked it.
Can everyone else reproduce this? For example, clicking on the Realplayer links on Amazon.com just downloads hurl.exe.ram instead of launching it automatically in Realplayer?