Unfortunately, while we have many of the boxed up standard business apps you mention, what we don't have, in the case of the company I work for, is legacy, in house application support. I work for a VERY large insurance company, yeah, I'm one of the IT guys, and while I would love to see OS X running across the board, it ain't gonna happen anytime soon.
We run literally dozens of apps that tie into everything from the mainframe, to Oracle, to SQL that we could simply NOT run on the Mac. Many of these are in house written stuff that dates back anywhere from 1 to 15 years. So no, Apple really doesn't do "business" very well if that business is anything outside of what most consider business apps. i.e. The stuff you mention, and of course all the graphical, design stuff.
I'm as big a zealot as anyone, but I have to face the facts at work as well. 🙁