who knows what may become of it when it reaches version 1.0?
Everyone who lost their XP install disk, or got burned by Vista might
want to keep an eye on this project.. a free windows XP binary compatible OS that is open source and free:

http://www.reactos.org/en/about_userfaq.html

Or, you could go with one of the many other Linux distros. A lot of commonly used software has ports for Linux these days, or similar software exists for the platform. You can also use WINE to run Windows programs, but being able to run them directly in a Linux system would be nice.

VMWare adds this functionality to MacOS, but for $80.

Quickbooks seems to be the silver bullet. As soon as that runs on linux or mac its over for MS. Yes, I hate quickbooks too, but its the gold standard for the paper pushers, and like the loathsome and ubiquitous .doc format for documents, if someone's gonna send you some financial whatnot its gonna be a .qif or a .qbb file. I'de love to see quickbooks disappear but with the size of the userbase it has, I don't see that happening soon. Hence a binary compatible to XP operating sense makes more sense for most businesses now until they release a linux version of quickbooks. And of course that is probably going to happen the day after the first-of-never. I have thought of trying it with wine, but are Intuit faithful to their own design betwen versions? They basically have every user locked into a forced upgrade path each year. If someone's got 2008 and you have 2006, you won't be able to open any file they send you, so you are stuck forking out the cash to upgrade. And when they move something or change a mechanism, will it work with wine without weeks of downtime to figure it out in the face of a closed lipped and unhelpful intuit support staff whose final answer will always be: "linux: not supported"?

devil and the deep blue sea problem, this one...

Quicken and QuickBooks Pro are both available for Mac. Premiere is still Windows-only, but the database server will run on Linux.

I still think that the biggest obstacle to Apple taking a larger section of the market, is cost. The engineering and software folks at Apple are great, but their marketing/sales people are still asking wayyy to much for their hardware. One way to bypass that, would be to release the OS for use on non-Apple hardware, but I doubt we'll ever see that while Steve Jobs is still alive.