Nothing?
1.) Full 64 bit OS including 64 bit kernel enabled on machines which you previously couldn't.
2.) TRIM support for Apple SSDs
3.) Better mail app
4.) Full screen support fantastic for smaller screens (think MacBook Air)
5.) Mission control unifies Expose and Spaces
You may not agree with the features, but I find them a significant step up from Snow Leopard.
Look, I just posted this (long) explanation on another thread. It explains our stance from the professional and business market as this isn't just about the OS:
In order to save time and space, I'l simply address comments made towards me without quoting as they seem to have the same (valid) points.
My issue is not just with Lion, it's with Apple's general direction. I've been developing and beta testing OS X since it was released, back when memberships cost $499+ (this new $99 fee is interesting as it seems Apple may want more consumer feedback when in the past it was purely meant for those who need to rework their applications with the new OS). I still have beta's from back in the Jaguar days with OS X features that were never released, some great ones that would be even perfect presently. This new deployment of monthly builds via the OS X App Store is odd, as before developers would receive beta's almost bi-weekly, with new features and system advancements, and these beta's would require being burnt to a DVD and installed from scratch (this ensured little compatibility issues). It seems the tables have turned, as an iOS developer as well we receive iOS beta's much more frequently compared to OS X updates (when there is one).
It's not just the software but the hardware. Apple's display line since the Studio line to the Apple Cinema Display line had more than one display option. Apple neglected their displays for almost eight years, and replaced a GREAT line that needed almost no tweaking with Spyder Monitor Calibration tools as OS X was coded to work perfectly with their displays. This allowed professionals such as myself all the way to photographers such as Annie Leibovitz to have a great system that produced uniform colors and a near perfect screen to print ratio. Apple simply replaced those displays with one, the same display panel used in their larger iMac. Certainly a cost effective move as the part's are already utilized, all that was needed was a simple tweak in the shell and voila, you have a display. However, one display does not fit all.
PowerMac G4 and G4's were priced around $1450+, and with a 23" or even 30" Apple Cinema Display, you had a great system for around $2500 or $3000. Now, Apple sells the Mac Pro for around that price, with only one display (now around $1000), and while a great display that used LED LCD panels for a great price, again, it's almost double what professionals invested in previous Apple products. Most of us need a powerful system that is upgradable, but we don't need expensive and power Intel Xeon SERVER processors and we need something more flexible than an iMac as most of us use more than one display and need more power for graphics and the such.
Not getting into it more, I'm not lamenting or trying to complain, most of us are disappointed as we have used Apple for our living well before the newcomers. I'm excited that Apple is doing amazingly well, but the company has $50+ billion in the bank. They went into a niche mobile market and made bank, and the professional and business market is not a niche market. Think of the thousands one business spends in upgrading their systems, that's just ONE business. If Apple utilized even a small amount of their cash reserve to re-focus on us, they could easily make a good amount of money and take much of the business market further from Windows/MS.
Alas, this does not seem to be an importance to Cupertino. So a lot of us are moving to systems and companies that seem to be interested in the business and professional market. This means all the time and money we have spent in Apple products is gone, and we have to reinvest in another platform, spending time and money we may not necessarily afford. It's a shame, but please don't dismiss us as complainers or whiners. We are adults, and unlike the majority of new comers, make our living using Apple systems. This is a big deal for us.