Being a consultant for a software development firm (building solutions for Newspaper publishers/printers based on 'Internet technology') I'm involved with a lot of demo's and document processing too. Doing all my work on a Dell laptop running Mandrake Linux for over two years I can assure you that there really is no real need to run Windows in a business environment.
I plan to 'swith' to a Powerbook very soon. My laptop (Dell Inspiron 8100 oldie) needs replacement and those Apples are really stylish and slick. The for me most important software packages run fine on the Mac:
Mozilla Firefox and
OpenOffice/
NeoOffice/J.
Goldmine is a CRM platform that only supports Windows unfortunately. If Goldmine is your company 'standard' you might have an issue there. If you use a stand-alone CRM sales tool you can easily swith to a Mac platform alternative.