I run a 4 year old ibook and really like it overall. My biggest complaints have been that the i-programs suck. I believe mac makes the best laptop for a casual/home user(me), but I would go back to a PC if I wanted a tower or had to run business apps.
You do know, don't you, that a Mac can run all those business apps? Every one of them, since it can run Windows.
I have Microsoft Office 2008 for Mac. I need it for school and am planning ahead for when I start working. I'm sure iWork is awsome only.. unfortunately.. how many businesses are compatible with those apps?