You crave the shiny goodness that is OS X 10.5 Leopard... we know you do. Still, you'd rather buy that new computer now instead of waiting for the chaos and long lines once the new system ships -- can you get a cheap upgrade? We now have the answer: with Apple's OS X Up-to-Date program, you're covered.
Any qualifying Macs (or XServes, for 10.5 Server up to date) purchased between October 1 2007 and December 29 2007 that ship with 10.4 Tiger are eligible for a $9.95 US upgrade to Leopard. Visit Apple's Up-to-Date page at http://www.apple.com/macosx/uptodate/ for program details and the necessary forms.