I will make it simple, but there are two suggestions that I have.

First- There should be an option to allow users to see the amount of total mail in a folder (example: Inbox (200) and then directly next to that when the user hovers over the 200, it will show them how many are new (example: **new** (2)

Second- There should be a shortcut to defer updates, such as in Access there is a checkbox.  I feel it is important to have this option/shortcut because those of us who have massive amounts of email and risk the program (not responding) need to defer the auto suggest.  Example

Say I want to do a search for themes, now I know themes only appears in 3 emails (for the sake of this argument assume this is true)  When I start to type t h e, the auto suggest feature automatically starts searching for all mail that contains the letters T H E.  I have had this happen a lot, especially when I am searching for a specific item and don't remember the exact phrase.

My suggestion is to allow users the option of either 

A.  Deferring the updates (halt the auto suggest)
B.  Make it an option, as in a checkbox when you search.

I hope this gets to Microsoft because Office 2010 is already herecoming soon.