Point of reference: Dell.com makes $50 million a day
Link, and only about half of their revenue comes via the web... (i used to work for dell home and small business online)
When having sales volume that's that high, it's not very feasable to just role out a whole line of new products... The amount of costs associated with R&D of new systems, testing all the different configurations, and all of their software on them, as well as the amount of personnel that would need to be hired to do this, makes little financial sense...
You'd have to relaunch the website with an updated configurator (the software that processes web orders) and because that puts orders directly into their order management system to be built, you'd have to update that system too, and it's large/archaic...
Not to mention additional supplier agreements, which of course affects Dell's much lauded supply chain - something that they wouldn't want to weaken...
I realize most of us are tech geeks and not MBAs but i don't believe that Dell would see an increase in business large enough to justify using AMD... Being Intel-only has allowed them to streamline their supply chain and keep costs down so their profit margin per box is much higher than their competition's, meaning they can set prices lower than the competition to win market share, and their product was always better to begin with anyway... This equals success which may not be enhanced, and more likely weakened, by using AMD as well...
And finally I don't know why you all care so much about it... Who here would buy themself a Dell if they offered AMD? And to the people who you refer to buy computers, if you tell them to go buy a gateway/compaq just because they offer AMD then that's unfortunate because their products just suck... No one I have known who has either of those bought one again... Whereas Dell gets tons of repeat customers...
Just my $0.02