I just bought a cheapie Dell to drive a TV and projector (I cancelled cable, since I never watch it), and they announced newer, faster, cheapie-er machines a week later. Such is life.
Also, I'd like to point out that the machine I use for all of my photo processing is basically a $600 Dell with a crapload of RAM shoved into it. You know, something like this:
DellSB - Dimension 4700 with P4 2.8Ghz 800 FSB, 256MB DDR2 SDRAM, 40GB HD, 48X CD-Rom for $529 after Rebate with FREE Shipping plus FREE 19" LCD and FREE Color Printer! [hwextreme.com, 2005-05-28]
... plus a couple gigs of RAM and a big hard disk. (It's actually a Dimension 8300, which can often be found for around $700, shipped.)
How the hell is that price possible, by the way? 'tis really, really, really cheap. And the machines are fast enough. Buy a few.