I'm going to go out on a limb here and say that people seem to like Leopard. Apple today announced that they have sold two million copies of Leopard since it went on sale on this past Friday. That's an insane amount of sales (the number includes copies sold at retail outlets, online, with new Macs, and via customers using the Up-to-Date program).
For comparison let's look at how Tiger did. Tiger went on sale on April 30th, 2005 at 6pm. Apple then announced 6 weeks later that the 2 millionth copy had just been sold. 5 weeks to sell 2 million copies isn't bad, but taking 5 days to do the same is incredible.
Leopard is a hit.