No, you do not need BootCamp or virtualization and absolutely no need to install Windows in order to run MS Office 2008 for Mac. It is the OS X version of Microsoft Office and runs natively on your Mac. In fact, it will not run in Windows.
The initial question was misleading, based on later posts. Am "assuming" your question is not about "Windows" which is their operating system, but about "Office" and installing Word, Powerpoint and Excel.
The primary negative reviews of Office 2008 for Mac are the same reasons why a whole lot of us don't like Office 2007 (which is the Windows version). That, and Entourage seems to be a far cry from the equivalent of Outlook in the Windows version.
If you don't want to use iWork, Neo Office or Open Office (the alternatives); then you only have two options basically (doesn't matter what's best).
Option one: You get Office 2008 for Mac - $235 at Amazon.
Option two: You get a copy of Windows and install it via Bootcamp or one of the virtual apps, and also get Office 2007. This could be done for anywhere between about $200 (with BootCamp, a system builder's copy of XP if you can still find one and Office 2007 for Home and Students) or all the way up to $900 (with VMWare Fusion, Vista Ultimate, and Office 2007 Pro). MS doesn't make anything easy.
My suggestion, get
Open Office for free and take
iWork for a free 30 day test drive. See if you really need any MS stuff on your Mac.