Just got a friendly tip/reminder via email from the National Association of Photoshop Professionals that I thought I would pass along:

If you happen to be working on an older version of Photoshop (Photoshop 6, 5, 4… you get the idea) then you can save some money upgrading to CS3 if you move quickly. You see, previously Adobe let anyone with a registered version of Photoshop (even Photoshop 2.0, etc.) upgrade to the latest version by simply paying the regular upgrade price. But, with the release of Photoshop CS3 , you’ll only be able to upgrade at the standard upgrade price if you have Photoshop 7, CS, or CS2. So, if you are still using Photoshop 6.0 or earlier, you should upgrade to Photoshop CS2 in the next few weeks (a cost of around $169), then you can buy the upgrade to CS3 when it comes out at the regular upgrade price. This workaround will literally save some of you hundreds of dollars over having to the buy a full version once CS3 and CS3 Extended ship.