Yup, for most users Parallels or another VM solution is the right approach. Bootcamp is much more specialized, I think. Well, if you are technically savvy enough to manage a vm. If not, I suppose Bootcamp is so simple even my mom can do it.
I just bought my first macbook but I also installed Windows 7 with Parallels. I considered boot camping windows but after reading a few threads and asking some friends I realized that theres a problem with the graphics card in bootcamp mode. Apparently Windows is graphics card hungry while boot camping and drains the battery life very quickly. If you absolutely need windows optimized to be as fast as it can be (and can deal with the loss in battery life) go ahead and bootcamp, otherwise vm is fine.
Bootcamp is useful if you want to boot only in Windows, and as others have mentioned, when you need to use the hardware only for it (given that you have the right software to take advantage of it).
If I recall correctly virtualization programs like Parallels and Fusion allow to also use the bootcamp partition as a Virtual Machine.
I have not have a need to use BootCamp in a while, and I have been using: www.virtualbox.org
(FREE) for a virtual machine.
If you use windows or linux more often than once a week, it would probably be better in the long run to have bootcamp or a virtual machine where you can run the OS on your system.