Mail.app smart views

What if Mail.app had "smart views" in a similar fashion iTune has "smart lists" ?

Wouldn't you like to be able to display "All e-mails received today", "Flagged e-mails", or e-mails in relation a specific address, sent out on a specific date/date range, etc. A little bit like Entourage, but much nicer.

They could appear in a tabbed view of the mailbox drawer.

What do you think of that ?

(cross posted on Apple Discussions)