Most of the EE's (and SW engineers) I know, including myself, use a Linux based OS with variants of Windows in a VM. Most of the tools many of us use (Cadence, Matlab, ISE, Quartus, Mentor, Spice variants, Modelsim, Synplify, etc., etc.). are optimized to run on Linux. There's a huge number of other advantages to using Linux for this type of work - ease of scripting (TCL / Python / shell / you name it), ease of off-loading simulations to dedicated machines - RDP can't touch X forwarding, superior HW/SW support for tools, and so on. Bottom line - efficiency is way higher in a measurable way - as we used to be forced to run windows only, with cygwin as our only unixy fix.
But I spend a fair amount of time with MS Office, and most of the corporate infrastructure is windows based. So the virtual machine solution is fantastic for me and my co-workers. Seamless mode (aka Unity for VMWare) is nice for some people, but personally I like minimizing Windows (and the accompanying flood of email) while focusing on detailed work (easily distracted). I frequently move files between OSes, and dual-boot isn't a solution - I personally think virtualization will stay the main way to run a multi-OS environment for a long time to come. I like the direction things are going, and am looking forward to running a true multi-OS environment at some point in the future (with a light weight HV running the show), when Host / Guest start getting irrelevant.
A little off subject, but while talking about OSes and electrical engineering, a rising trend that is driving me nuts is that so many of the scope and logic/spectrum analyzer manufacturers are running windows as their OS - and they brag about it in their marketing materials. The only thing I can think of is that many engineers don't get to pick the specific scope they get, and the purchasing or mgmt types think having XP on a scope is just fantastic. In an environment with security issues, Windows has to be locked down so hard it needs 2 or 3x the RAM a normal install would, and I frequently end up with $25k scopes which perform worse then their 15 year old equivalents. Ask a sales rep from one of these companies about offering Linux (or whatever) alternative OSes, and you get a 'wtf is wrong with you?' look.
It's nice that so many of you put yourselves up on a pedestal that lets you see what all people in the 'real' world are doing with OSes. And to reference the GPs 'out' - EE /= Circle of Geeks (although I'll give you that there is pretty strong correlation).