I'm shocked at how many people are so willing to just wave away all the nice under-the-hood changes and improvements that Lion offers just because there aren't any super-radical UI changes... really disappointing to be honest. Does it really have to be all flashy to be of interest to you? What, the functional side of things doesn't matter any more?
As an amateur OS X developer, I really hate this attitude because it will end up slowing Lion adoption. That really sucks, because there are a ton of awesome changes in 10.6 that I (and many, many other developers) would love to take advantage of to make their software even greater, but it's not going to be viable to go Lion-only for said features until Lion is installed on the majority of Macs out there.