Thanks for the responses people, that was quick!
I've tried that tray icon app previously and although it kinda works, it's not ideal. You can't seem to get Windows Mail to minimize directly to the tray, you have to click the tray icon and choose hide. Neither does it offer nice pop up previews of new mail like Outlook does.
I'm curious about Live Mail Beta though and think I might give that a whirl, does it replace Windows Mail or run alongside it? One thing I didn't like about XP was having Outlook Express and Outlook on the same system, I've always wanted one definitive mail app and I was hoping Windows Mail would be it. Unfortunately it now seems that it could be Windows Mail, Live Mail, Outlook or a combination of them all!
What advantages/disadvantages does Live Mail offer in comparison to Windows Mail?
I really like some of the Live Ideas but they don't seem that well intergrated yet, I had hoped a while back that a lot of the current ideas and Live apps would be integral to Vista but that still seems a long way off.