Since Dell is a US company I thought a little US law perspective might be handy. (IANAL)
Bait & switch
"It’s illegal to advertise a product when you have no intention of selling that product at the advertised price. Bait and switch tactics are illegal, period. If you advertise a product, the law says that you have to intend to sell it as advertised."
Advertising Law: Mis-marked Price
" If a product is marked or advertised at a certain price, your state laws may require you to sell it at that price. Check with your state's Attorney General’s Office."
And the little bit of research I did on the laws in Texas say that if you advertise it at that price, you must sell it at that price, even if it was a misprint or mistake.
So on the face of it, it would appear that Dell is screwed. The advertised it, they accepted payment for it at the price advertised, and they must now deliver the goods. If they tried to weasel out of it like they are currently doing, in the US they would get their asses sued off, and LOSE. I hope Taiwan makes them wear a good and proper asshat.