I read that article too.....
But as others already said, it only really proves that the new iMac is a great value for a *home* user, wanting a system that's fast for typical home/office applications.
If you're into a lot of computer gaming, you want the Mac Pro because of better video card options like the Radeon X1900XT with 512MB of video memory. A Mac Pro, configured this way, will soundly outperform any iMac at 3D gaming. (I can boot into Windows XP on my Mac Pro and play Bioshock with all detail levels at high/maximum, on my 24" display using the native 1920x1200 resolution,and it's very playable. Doubt the same can be said for a 24" iMac.)
You also want a Mac Pro if you need lots of drive space. A Mac Pro makes it easy to install (and swap in/out as needed in the drive trays) as many as 4 SATA drives at a time. With 1TB SATA drives now available, that means you can have 4 terrabytes of storage in a Mac Pro without even plugging in anything external. On an iMac... not so much.
And all of this is before we even start discussing the "Pro" type apps, designed to make full use of multiple dual-core processors.
Just read a speed test of iLife '08 apps at this URL:
http://www.macworld.com/2007/08/firstlooks/ilife08/index.php
You'll notice that a new aluminum 24" iMac is faster than a 2.66 Mac Pro at iDVD and only a few seconds slower at EVERYTHING ELSE! If you have a need for a REASONABLY PRICED and fast Mac right now, get the iMac and save a bundle. If you need upgradability then wait for the updated Mac Pro. I was thinking of getting a MP off ebay or a refurb from Apple, but this clinches it. I'm waiting!