Most importantly to me, (since for all my bitching, I spend a lot of my work time writing Mac software) Xcode went from 'spectacularly awful bag of suck' to just 'kinda sucks', and ARC, blocks, Objc-2, non-insane literal syntax are all forces for Good.
And yes, I love inverse ('natural') scrolling and it is enabled on all my Macs. :)
It's not that Apple does nothing at all good, it's that their focus has become even more relentlessly "systems that the average shopper at walmart can use" at the expense of those users who have a stronger grasp of general computing concepts.
When they disable all the extra screens in fullscreen mode, the chances of my dad getting confused and looking at the wrong monitor are reduced. But at the same time, the amount of data I can see at once, and my ability to manipulate it, are also reduced.
Go look at that page real quick and count the number of things that are good. Not "not bad" or "you can turn it off". Good.
Anyway, an OS is more than the sum of its newest features. On the whole, OS X 10.8 is a stable, polished, powerful, fully-featured operating system. There might not have been a big feature like Time Machine or Exposé in a couple versions, but I'd much rather use 10.8 than 10.5.
I think 10.7 and 10.8 bring more irritations than anything else. iCloud sync and Gatekeeper are the only things I think are worth upgrading for, but the Gatekeeper implementation is still lacking and unfree, and I use other services to sync my files (I also think the implementation of iCloud leaves something to be desired... and it's another form of lock-in). I'm still using 10.6 and shall use it for the foreseeable future; at least until my next computer, which will most likely be running Linux.
Remember when every Mac shipped with an IR port and a little remote? Laptops shipped with remotes. But apparently an optional app chooser interface (LaunchPad) is the most anti-PC they've ever shipped.
If front row still existed, I wouldn't be throwing away my 08 blackbook. It's not really powerful enough to be a server, but it would make an awesome HTPC.
Notification Center is a list of notifications you can turn off if you don't like notifications. What's the big deal?
Launchpad is a little icon you can click to see your apps. What's the big deal?