Intel Macs running OS X, Linux, and Windows
This is big, at least to me. I use two laptops and two desktop PCs (and some leased hosted servers) for my business: 2 Macs and 2 dual boot Linux/Windows boxes. I don't like clutter in my home office, and the idea of one high end Intel Mac laptop (with an external monitor for desktop use) that is OS X/Linux/Windows capable sounds great to me.
I absolutely don't mind rebooting since I usually need to use one OS for a while, depending on what I am working on. As I have written before, the secret to no hassle switching computers and operating systems is a CVS server so you can sync up development assets easily on any computer (cvs or svn update is your friend :-)