In my opinion - no. If you don't have any problems with Windows, there's really no reason to use it. I've used it before, but after a day or so I always go back to Windows.
Although i haven't explored the linux world yet, I do have to agree with the dual boot option as a way to go. And I heard that the new Dell computers will come with a dual boot option and linux pre-installed on them.
Linux is nice, but I don't use it primarly. I would rather Windows because of compatibility (though Vista is so-so on that). Vista has lots of free open-source programs available to download too for it. If you like it, why not dual-boot? It won't hurt anything.
I've got Ubuntu dual booted with Windows XP but I don't use it that often. I sort of got frustrated trying to set it up for programming since it was just being a complete hassle so i have left it alone for now. I still like having it though in case windows f***s up something lol. So is it worth it? To some, yes, to others, definitely not. I did vote yes though