Last night I almost took the plunge into Linux...almost.
I remember decades ago sitting at a screen next to one of the masters of Unix, who was munging out a device driver or some such, and him telling me that there were two types of coders, and those that didn't habla grep, awk and all of the other caveman-like utterances used in that world were developers of the 'other' type.
In the other room, a wi-fi leap away, I have a Windows XP box that I use as a file and print server, a new used Mac blueberry thing that, for the moment, I use primarily to test sites on Mac browsers, and another PC on which I have Ubuntu, which I'm making into a net server for testing. My laptop runs Vista, but I've recently added Sun's VirtualBox and have Win XP running on it (for the, hopefully, final days of IE6 site testing), and Ubuntu.
So, with Ubuntu on two boxes, why am I not using it all the time? Mainly because of software investment. I use both OpenOffice and Office...some things OpenOffice just will not do...yet. I use Retrospect for backups, QuickBooks, Paintshop Pro, Adobe Create Suite, phpEd for development, and so forth. I realize that I could use Ubuntu all day long, and switch back to Vista when needed...and I'm getting closer.
I'm running Wamp with a few dozen web sites sitting on it, one even using Tortoise SVN. Last night I posted a contributed module to Drupal.org, and for that one uses CVS. phpEd comes with CVS, sort of. I needed to tag the committed code with a Drupal-style version, and the context menu didn't offer tagging at all. So my next step was to download Tortoise CVS, which supposedly has problems with Vista. It turned out that the only issue was when it wanted to restart Windows Explorer. Apparently Explorer resisted with gusto, but simply bringing up the task manager and killing Explorer's process allowed the install to finish, though Explorer never fully restarted, so I had to reboot later. It seems to work fine.
Had Tortoise CVS not worked, I was prepared to install LAMP under Ubuntu, find an OpenSource IDE and take the plunge.