One thing that Windows and Outlook have always had up on the Mac's default email and calendar apps, Mail and iCal, is Outlook's integrated to-do manager. Today the game changes. Leopard's new Mail and iCal applications introduce their own take on the email- and calendar-integrated to-do list. So now the question is: Is it any good? The answer: Yes. And no. But probably yes. The To Do manager, at the moment, is a bit of a mishmash of some very good and a few bad—or at least unrealized—features.
The Mail.app To Do feature resides in the Reminders panel of the Mail sidebar below Notes. Mail to-dos can be organized by due date, priority (high, medium, low, or none), title, and calendar (that's right, they also integrate with iCal). You can create a new to-do in a couple of ways.
First, click the To Do button in the toolbar. You'll jump straight to the To Do window, where you can enter the details of a new item. Alternately, you can create your to-dos from Notes (another new feature in Mail). Once you've written a note, you can convert any line of the note or the entire note into one or several to-dos. The strange-yet-interesting thing about to-do notes is that the new to-do will appear in the To Do screen as well as the note, and you can check it off in either place. In fact, you can check off to-dos in a third place as well: iCal.
iCal's organisation of to-dos is much more convenient than Mail's To Do view, if only for its more prominent focus on due dates and priorities and its sidebar display (so you can view to-dos along with application content). To get a look at your to-do list within iCal, just click the thumb tack button on the bottom right of iCal. From there, you can check off your to-dos, re-prioritise, or change other information by double-clicking the item.
My biggest gripe about Mail's implementation of to-dos is that you can't create a new to-do from an email (or anything else, for that matter) via drag and drop. Also, the Notes integration is completely bizzare since Apple dropped the ball on supporting iPhone-to-Mail syncing of notes. As is, it comes off like a pointless appendage to Mail.app.
Another little bug I ran into: I couldn't change the due date of a to-do from Mail when iCal was open. Instead, I had to change the date inside iCal—though I would assume this will be fixed with an update.
In the end, to-do lovers have a promising addition to Apple's email and calendar apps, but considering the breadth of full-featured alternative to-do list managers that have popped up in the absence of one from Apple (including ones that integrate with iCal in one way or another), it's tough to say whether Leopard's To Do feature will catch on for the hardcore list keeper.