Hum, there doesn't didn't see a way to setup ide in Fusion via the gui -- hard drive options are greyed out. Not sure if it's a pre-release thing or what. Digging into the cl tools right now.
As for running native OSes..
uelsk8s, does rEFIt have a hide command like grub? Here's, for example, how I'm using Grub hide/unhide on my PC.
title WindowsXP (on /dev/hda1)
title WinTesting (on /dev/hda2)