Outlook 2010's Conversation View And Protected View
Love it or hate it, Gmail's use of the "conversation" metaphor instead of folders was a big change for e-mail. Outlook 2010 borrows the concept, and actually improves on it in couple of ways.
First of all Conversation View is an option for particular e-mail messages, not your only choice for dealing with your inbox. It's designed to help users clean up the large volumes of e-mail they get. (Microsoft says the average person gets 1,800 e-mails per month, and deletes 1,500 of them.)
Many of those e-mails come as part of endless threads on which you're cc:ed but not interested. You can select Conversation View to deal with the mess, condensing the thread to a single line, Gmail style, while leaving the rest of your inbox as is. It even works when some messages in the thread are in other folders.
Better still, you can "Ignore" a conversation and Outlook 2010 automatically deletes all messages in the thread -- and even deletes new messages that come in to it.
Outlook 2010 also adds a new Protected View that opens Microsoft Office docs you receive via e-mail in a special "sandbox" where they can't harm your system. You can view the document, but have to mark it as "Safe" to edit it. Once marked Safe, it's trusted from then on and opens normally.
Best of all, the IT department can manage which sources and file types trigger Protected View.