In Outlook 2000, I got a little envelope on my task bar notification area to indicate a new email item. I still get that, but I also have an Outlook icon to remind me that Outlook is still running. Of course, it's hard to forget Outlook is running when it doesn't minimize properly.
I Alt-Tab between applications a lot. Say I've got Firefox and gVim open at the same time. If I minimize Firefox, it goes to the end of my application list for Alt-Tabbing. That makes sense. I've just minimized it, I probably don't need it right away again. This applies to every program except Outlook. If I minimize Outlook, it stays at the top of the Alt-Tab list. The only way to demote it is to Alt-Tab to all the other running applications.
I can't click links in preview mode. I have to open the email message. I could use the ginormous "reading pane", but it bugs me so much. Why do you insist on formatting my emails to look like memos? Agh. Dumb dumb dumb.
Finally, thanks for the browser built into Outlook. I really needed that. It makes finding security fixes so much easier to look for, if not find.