>Anecdotal evidence. My experience is precisely the opposite. The Linux desktops were dead-easy to set up. Everything we need Just Worked. And ongoing maintenance is a breeze.
With ActiveDomain membership, centralized backup, etc.? I doubt it. You need to buy something like SuSE for that and it ain't cheap.
Again, Linux might be OK for you on desktop, but it certainly is not significantly better than Windows. And given that Windows+Office is pretty cheap - there's simply no business case for small-to-midsize companies.
Then there's question of home users. I'm not a Mac fanboi (I just like MacBook's Retina display too much), so I don't have any other Apple hardware (well, I also received an iPad as a gift) - my phone is Android-based. But I've seen people with all-Apple infrastructure at home: TimeCapsules for backup and WiFi, Apple TV to view movies rented on iTunes, iPods for home sound system, etc. Integration is really impressive and mostly JustWorks. Windows comes at close second and is slowly getting better. I know people who use Windows Media Center to play music over multichannel and multizone sound systems.
Linux? Nah, we still can't get one decent media player/manager.
So yes, I'm pessimistic. It doesn't seem like Linux is capable of catching up with classic desktop computers.