My thoughts:
The "default" desktop version of FC3 does take more resources than a "freshly" installed Windows, but:
(1) Nowadays, hardware is so cheap, 512 MB or even 1 GB RAM has become a norm, and it is quite difficult to find a CPU that is slower than 2 GHz (real or normalized). For most users, especially business users, resource requirement has become a largely irrelevant issue.
(2) FC can be customized so that it can run very snappily even under resource-constrained devices (such as PDA or handheld), or old systems. Most FC users-wanna-be probably don't have any idea of how to customize an FC installation, but that's what consultants are for. Right? Can anyone think of a business entity which does not have a service contract with a Windows consultant?
(3) While Windows can be very snappy when fresh, it is notorios for showing gravely deteriorated performance after time, especially after you have installed a number of applications. With FC, thanks largely to the free upgrades, its performace actually goes up with time.
Of course, Windows is OK if you don't use it to surf the internet.
