The reason I'm not going to Leopard is Time Machine.
I mean, say what you will about Wikipedia - it's a community driven site, and some things will be wrong while most others are right. But still, yes, agreed, it's a terrible idea to include access to a site which might provide updated information when, as we all know, dictionaries should be static and unchanging.
But Apple really burns my butt calling that feature "Time Machine". I mean, there's absolutely no time travel involved whatsoever, and so I think it's deceptive advertising. I feel terrible for the people lined up tomorrow expecting wonders for $129 and being terribly disappointed when they open the box. I especially feel bad for the children and seniors, who are so often the target of this sort of marketing exploitation.