How many do YOU own ...?
The Dell desktop with its 22" screen is still my platform of choice for web development. I can boot it into LinuxMint or Windows 7, and the ample display size is great for keeping multiple windows open. It has enough horsepower to run Windows XP in a virtual machine with VirtualBox while simultaneously playing music and browsing the Internet. For spreadsheets, document formatting, web pages, graphic design, and games, this is the place to be. It's a year and a half old with "only" a dual core processor, but 8 gigs of RAM keeps it going smooth as silk.
And when deciding whether to use the netbook or tablet, it's easy: am I going to be typing or reading? For us inveterate touch typists there is no substitute for real keys. I've tried a bluetooth keyboard with the Nexus and it feels OK, but if I'm going to put the keyboard on my lap where do I put the tablet? The netbook is a typewriter, amplified. And the tablet is a book, electrified. Simple as that.
Now it seems as if the Nexus tablet is just a grown up version of the phone. It still runs Android with its wealth of apps and beautiful integration with Google's wide world of services, but now with a form factor that feels like a book and performs like a personal TV. Dare we imagine that a desktop version is in our futures? Rumor has it that Google is about to merge Android with its Chrome operating system to put the final desktop nail in the Microsoft coffin. Or if you don't care for that scenario, how about integrating a tablet with your home entertainment system? It can be done even now if you can assemble all the bits and pieces, but it's easy to imagine it becoming a seamless standard.